Low Testosterone in Older Men: When to Consider Hormone Replacement Therapy

Introduction

Testosterone is a natural hormone that plays a major role in men’s health. It helps maintain muscle mass, bone strength, red blood cell production, sexual function, and mood. During puberty, testosterone is responsible for the development of deeper voice, facial hair, and growth of the male reproductive organs. In adulthood, it continues to support physical vitality, energy levels, and overall well-being. However, as men age, their testosterone levels slowly decline. This decline is part of the normal aging process, but for some men, the drop is steep enough to cause noticeable symptoms and health problems. Understanding when this becomes a medical issue—and when hormone replacement therapy (HRT) might help—is an important question for many older men today.

Research shows that testosterone levels start to fall gradually, typically about 1% per year after the age of 30 or 40. For some men, this slow decrease may not cause any clear symptoms. Others, however, experience fatigue, reduced muscle strength, lower sex drive, and mood changes. These symptoms can overlap with other common health problems such as depression, sleep disorders, or side effects of medications, making it difficult to know if “low T” (low testosterone) is truly the cause. Because of this overlap, doctors stress the importance of careful evaluation and testing before deciding on any treatment.

The issue of low testosterone in older men has gained more attention in recent years. Many advertisements and online sources claim that testosterone replacement therapy can reverse aging, boost vitality, and improve mood or sexual performance. However, the medical evidence is more complex. While testosterone therapy can help men with genuine hormone deficiency, it is not a cure-all for aging. In fact, it carries potential risks if used inappropriately, such as thickened blood, prostate issues, or worsening sleep apnea. For these reasons, professional medical groups recommend that testosterone replacement be prescribed only after a clear diagnosis of testosterone deficiency—also called hypogonadism—has been made through blood tests and clinical evaluation.

This article aims to answer the most common and important questions that older men have about testosterone and hormone replacement therapy. Many men who search online want to know: What level of testosterone is considered low? What symptoms should I look out for? What causes testosterone to drop, and when should I consider therapy? Others wonder about the benefits, the risks, the types of treatment available, and what monitoring is needed if therapy begins. These are valid and complex questions that deserve clear, science-based explanations.

To give readers a complete understanding, this article will explore testosterone in aging men from multiple angles. It will begin by explaining what is considered a “normal” testosterone level and how these levels change over time. Next, it will describe the typical symptoms and medical causes of low testosterone, showing how doctors distinguish between normal aging and true deficiency. The discussion will then move to when testosterone replacement therapy is appropriate, what benefits it may offer, and what possible side effects to watch for. Later sections will explain how therapy is given, what monitoring is required, and which men should avoid treatment altogether. Finally, we will review what is known about the long-term safety and effectiveness of testosterone therapy in older men.

Understanding these issues is essential because testosterone therapy is not a simple or one-size-fits-all solution. Each man’s health, symptoms, and hormone levels are unique. Deciding whether therapy is appropriate requires a thoughtful, evidence-based approach that considers risks and benefits. For example, a man with mildly low testosterone but no troubling symptoms might not need treatment at all. On the other hand, a man with very low levels and clear symptoms of deficiency—confirmed by testing—might benefit significantly under a doctor’s supervision. The key lies in identifying which situation applies, and that can only be done through proper evaluation.

Equally important is understanding what testosterone therapy can and cannot do. While it may improve libido, mood, and muscle mass in men with low hormone levels, it is not proven to prevent heart disease, restore youth, or extend lifespan. Public messaging often exaggerates its effects, leading to confusion and unrealistic expectations. Therefore, one goal of this article is to separate fact from myth and give readers the knowledge they need to have informed conversations with their healthcare provider.

In summary, low testosterone in older men is a common issue, but not every man with a reduced level requires treatment. Hormone replacement therapy can be useful for those who truly have testosterone deficiency and bothersome symptoms, but it must be approached carefully and monitored regularly. This article will walk through the evidence and guidance step by step, answering the top questions men have about testosterone therapy so they can make safe and informed choices about their health.

What Counts as “Low Testosterone” in Older Men?

Testosterone is a hormone made mainly in the testicles. It helps control muscle growth, bone strength, red blood-cell production, and sexual function. Every man’s testosterone level changes over time. It rises during puberty, stays high through early adulthood, and then slowly begins to fall as men get older.

Doctors call this hormone testosterone “T” for short. When it drops too low, a man can develop a medical condition called hypogonadism or testosterone deficiency.

Understanding Testosterone Levels

Doctors usually measure testosterone in a blood test. The most common measure is total testosterone, which includes both the hormone attached to proteins in the blood and the small “free” portion that is active in the body.

A typical healthy adult man may have total testosterone levels between 300 to 1,000 nanograms per deciliter (ng/dL). Levels below 300 ng/dL are often used as the cutoff for “low testosterone.” However, this number is only a guide. It is not the same for everyone, and it can vary from lab to lab.

Free testosterone—the part not bound to proteins—is sometimes checked when total levels are borderline or when a man has symptoms but the total testosterone seems normal. Free testosterone gives doctors a clearer picture of how much active hormone is available for the body to use.

How Testosterone Changes with Age

It is normal for testosterone levels to slowly fall as men age. Starting around the age of 30 to 40, testosterone levels may drop about 1 percent per year. By age 70 or 80, a man’s levels may be 30 to 50 percent lower than they were in his twenties.

This steady decrease is part of normal ageing. But in some men, the drop becomes large enough to cause noticeable symptoms such as tiredness, low sex drive, or mood changes. When the level falls below the lower limit for age, or when symptoms become troublesome, doctors consider whether the man might have late-onset hypogonadism—a medical condition beyond normal ageing.

Normal Ageing or True Deficiency?

Not every man with a lower testosterone level needs treatment. This is an important point. Ageing itself causes many of the same symptoms that appear with low testosterone—fatigue, less muscle, weight gain, and lower sexual desire.

To decide whether a man truly has testosterone deficiency, doctors look at both numbers and symptoms. A low number alone is not enough. A man must also have consistent symptoms that fit the pattern of low T.

For example, an older man with mild tiredness but normal muscle mass, mood, and sexual function may not benefit from therapy even if his level is near the low range. On the other hand, a man with clearly low energy, reduced strength, and erectile problems plus low measured testosterone on more than one test may have true hypogonadism.

The Right Way to Test for Testosterone

Because testosterone levels rise and fall during the day, timing matters. They are highest in the morning, usually between 7 a.m. and 10 a.m., and lowest in the evening. That is why doctors always ask for a morning blood sample.

If the first test shows a low level, a repeat test is done on another morning to confirm it. This second test is important because temporary factors—such as poor sleep, illness, heavy exercise, or certain medications—can lower testosterone for a short time.

When doctors suspect low testosterone, they also check other hormones, such as luteinizing hormone (LH) and follicle-stimulating hormone (FSH). These tests show whether the problem starts in the testicles (primary hypogonadism) or in the brain’s control centers, the pituitary and hypothalamus (secondary hypogonadism). Sometimes, imaging or further testing is needed if the results suggest another cause.

Lab Variations and Individual Differences

Each laboratory may use slightly different testing methods and reference ranges. What one lab calls “low,” another might consider “borderline.” In addition, testosterone levels vary from person to person. A level that feels normal for one man may cause symptoms in another.

This is why the diagnosis must always involve both clinical judgment and lab results. The doctor compares the test results, the man’s age, his overall health, medications, and his specific symptoms before deciding whether he truly has low testosterone that needs treatment.

Factors That Can Lower Testosterone Levels

Many things can temporarily or permanently lower testosterone. These include:

• Obesity: Extra body fat, especially around the belly, can reduce testosterone levels.

• Chronic illness: Conditions such as type 2 diabetes, liver or kidney disease, and infections can suppress hormone production.

• Certain medications: Long-term use of steroids, opioids, or some antidepressants may reduce testosterone.

• Sleep problems: Sleep apnea or poor-quality sleep can interfere with hormone release.

• Stress and alcohol use: Both can affect the body’s hormone balance.

Understanding these causes helps ensure that a low testosterone reading is not just a temporary change that could be fixed by treating another problem.

Key Question: What Testosterone Level Is Considered Low in Older Men?

Most experts agree that a total testosterone level below 300 ng/dL, when combined with symptoms, signals low testosterone. Some guidelines set the threshold slightly higher or lower, depending on the lab and the patient’s condition.

However, doctors stress that the number alone does not tell the whole story. Many older men have levels in the lower range without major symptoms, while others experience significant symptoms at slightly higher values. The key is whether the low level is causing real health problems and whether raising it would improve quality of life and function.

Low testosterone in older men is common, but defining exactly what counts as “low” is complex. It depends on both blood test results and how a man feels. A diagnosis should be made only after at least two morning tests show low levels and the man has symptoms that fit the pattern of testosterone deficiency.

Ageing naturally lowers testosterone, but not every decline needs treatment. Careful testing, interpretation, and discussion with a healthcare professional help separate normal ageing from true hypogonadism that might benefit from therapy. Understanding how testosterone is measured—and what those numbers really mean—is the first step toward making informed decisions about hormone health in later life.

What Symptoms Might Suggest Low Testosterone in Older Men?

Testosterone plays an important role in many body functions in men. It affects physical strength, mood, sexual health, bone density, and even how the body uses energy. As men age, testosterone levels naturally go down, usually starting around age 30 or 40. This decrease is slow—about 1% each year—but over time it can become noticeable. For some men, the drop in testosterone is mild and causes no problems. For others, the level may fall low enough to cause symptoms that affect daily life.

Understanding the signs of low testosterone—also called male hypogonadism—is important. Some symptoms can be subtle or may seem like part of normal aging. Others can overlap with different health conditions, which is why it is important to look at the whole picture, not just one or two symptoms.

Physical Symptoms

Low testosterone can change the way a man’s body looks and feels. One of the most common signs is reduced muscle mass and strength. Testosterone helps build and maintain muscle tissue. When levels drop, muscles may shrink or feel weaker even if a man keeps the same activity level. Lifting heavy objects or exercising might become harder than before.

Another physical change is increased body fat, especially around the belly. Some men notice their weight goes up even if they have not changed how they eat or exercise. Low testosterone can also affect how the body burns fat and stores energy.

Low testosterone can lead to thinner bones or osteoporosis over time. This means bones can become more fragile, raising the risk of fractures. Bone loss usually happens slowly, so men may not notice until they have an injury or are tested by a doctor.

Other body changes include reduced body hair, smaller testicles, or swelling in breast tissue (called gynecomastia). Some men also feel hot flashes, similar to what women experience during menopause.

Sexual and Reproductive Symptoms

Testosterone has a key role in sexual health. When levels are low, a man may experience lower sex drive (libido). He may feel less interested in sexual activity or find it harder to become aroused.

Erectile dysfunction (ED) can also occur, though low testosterone is only one possible cause. Many older men have ED due to other reasons, such as poor blood flow, diabetes, or certain medications. Still, testosterone helps support the chemical signals that start and maintain an erection.

Low testosterone can also affect ejaculation and orgasm intensity. Some men notice fewer spontaneous erections, such as those that occur during sleep or early in the morning.

Because testosterone helps produce sperm, very low levels can reduce sperm count, which can lead to fertility problems. While fertility is often less of a concern for older men, this effect is still worth noting.

Emotional and Mental Symptoms

Hormones can strongly affect mood and thinking. Men with low testosterone may feel tired, depressed, or less motivated. Some describe it as a “flat” mood or loss of interest in activities they once enjoyed.

It is also common to feel more irritable or anxious. Concentration and memory may decline slightly. Some men notice that they find it harder to stay focused or that their mental sharpness is not the same as before.

Because these changes can also be caused by stress, sleep problems, or other illnesses, low testosterone should be confirmed with proper testing—not assumed based on mood alone.

Energy and Sleep Changes

Many men with low testosterone report a drop in energy or constant fatigue. Even after a full night’s sleep, they may still feel tired or sluggish during the day.

Some men also experience trouble sleeping. Low testosterone is linked with sleep disturbances such as insomnia and sleep apnea. Sleep apnea, in turn, can further lower testosterone, creating a cycle that worsens both conditions.

Symptoms That Overlap with Other Conditions

It is important to remember that many of these symptoms are not unique to low testosterone. Conditions like obesity, diabetes, thyroid disorders, depression, or chronic stress can cause similar changes. Certain medications—especially opioids, steroids, and some antidepressants—can also reduce testosterone levels.

Because of these overlaps, doctors rely on both symptoms and blood tests to make a diagnosis. A single symptom, such as fatigue, is not enough to confirm low testosterone. The best approach is to look for a pattern—for example, reduced libido, muscle loss, and fatigue together—and then measure hormone levels with a morning blood test.

When to Talk to a Doctor

If an older man experiences several of these symptoms, especially sexual changes combined with low energy or mood changes, it is wise to discuss them with a doctor. The doctor can order tests to measure testosterone and check for other possible causes.

A diagnosis of low testosterone usually requires two separate blood tests taken in the morning, when testosterone levels are highest. If both results show low levels and the symptoms match, the doctor may consider treatment options or look for underlying causes.

Low testosterone can affect the body, mind, and emotions in many ways—ranging from muscle weakness and weight gain to fatigue, mood changes, and reduced sexual desire. However, these signs can also come from other common health problems. Recognizing the full pattern of symptoms and getting proper testing are the first steps in understanding whether low testosterone is truly the cause.

For older men, awareness and early discussion with a healthcare provider are essential to finding the right diagnosis and treatment plan.

What Causes Low Testosterone in Older Men (Beyond Normal Ageing)

Testosterone levels naturally drop as men get older. On average, levels begin to fall about 1% per year after the age of 30 or 40. However, not all low testosterone is simply part of getting older. In some men, the decrease is greater than expected or is caused by an underlying medical problem. Understanding the possible causes helps doctors decide when hormone replacement therapy (TRT) might be appropriate and when other treatments are needed.

Primary and Secondary Hypogonadism

Low testosterone, also known as hypogonadism, can occur for two main reasons — a problem in the testicles themselves, or a problem in the brain areas that control them.

Primary hypogonadism means the testicles cannot produce enough testosterone, even though the brain is sending the right signals. This can happen because of:

• Age-related testicular decline – testicular tissue becomes less efficient at making hormones over time.

• Genetic conditions such as Klinefelter syndrome, where men have an extra X chromosome.

• Injury or infection of the testicles (for example, mumps after puberty).

• Chemotherapy or radiation therapy for cancer, which may damage the testes.

• Certain medications that affect testicular function, such as long-term steroid use.

Secondary hypogonadism occurs when the hypothalamus or pituitary gland — parts of the brain that signal the testes to make testosterone — are not working properly. Causes include:

• Pituitary tumors or other growths that interfere with hormone production.

• Head trauma or surgery that affects these brain regions.

• Chronic illness or inflammation that suppresses the hormonal pathway.

• Obesity and metabolic syndrome, which can lower the release of key hormones like luteinizing hormone (LH).

• Medications such as opioids or glucocorticoids that suppress the hypothalamic-pituitary-gonadal (HPG) axis.

In many older men, both primary and secondary factors contribute, creating what doctors call late-onset hypogonadism — a mixed picture where the entire system is less responsive.

The Role of Ageing

It is normal for testosterone to decrease gradually with age, but the rate and impact vary widely. Some men in their 70s maintain healthy levels, while others experience sharp declines. Ageing affects several parts of the hormone system:

• The testes produce less testosterone.

• The pituitary gland releases less LH, the hormone that tells the testes to work.

• The sex hormone-binding globulin (SHBG) level increases, binding more testosterone and leaving less “free” (active) hormone available.

Because of these changes, many older men have lower total testosterone, but not all have symptoms. Low levels alone do not always mean a disease is present.

Health Conditions That Lower Testosterone

Certain medical conditions can lower testosterone by disrupting how hormones are produced or used in the body. Common ones include:

• Obesity: Fat tissue converts testosterone to estrogen through an enzyme called aromatase. Higher body fat often means lower testosterone and more estrogen.

• Type 2 Diabetes: Insulin resistance and high blood sugar damage the hormonal signaling between the brain and the testes.

• Chronic diseases: Conditions like kidney disease, liver disease, or HIV can reduce testosterone production.

• Sleep apnea: Poor sleep and low oxygen at night can suppress testosterone secretion.

• Thyroid disorders: Both overactive and underactive thyroid glands can disturb hormone balance.

When these conditions are treated or controlled, testosterone levels may improve without the need for replacement therapy.

Medications and Substance Use

Several drugs and substances can reduce testosterone levels. These include:

• Opioid painkillers, which interfere with the brain’s hormone signals.

• Glucocorticoids (like prednisone), which suppress the pituitary gland.

• Certain antidepressants and anti-anxiety medications.

• Chemotherapy drugs, which can directly damage the testes.

• Anabolic steroids used for bodybuilding — these can shut down the body’s natural testosterone production once stopped.

• Excess alcohol and recreational drugs such as marijuana can also have a negative effect on hormone levels.

Older men often take several medications for chronic conditions, so it is important for doctors to review all prescriptions and possible side effects before starting TRT.

Lifestyle and Environmental Factors

Lifestyle habits also play a role in lowering testosterone:

• Lack of physical activity reduces muscle mass and increases fat, which leads to lower testosterone.

• Poor diet high in sugar or processed foods contributes to obesity and insulin resistance.

• Chronic stress increases cortisol, a hormone that suppresses testosterone.

• Exposure to endocrine-disrupting chemicals — such as phthalates, pesticides, or BPA — may interfere with hormone production.

• Inadequate sleep reduces nightly testosterone surges, as most testosterone is released during deep sleep.

Improving these factors can sometimes raise testosterone naturally and may delay or reduce the need for hormone therapy.

Distinguishing Normal Ageing from Disease

One of the biggest challenges is telling the difference between normal age-related decline and clinically low testosterone that needs treatment. A doctor will look for both low test results and symptoms like low libido, fatigue, or muscle loss. Two morning blood tests showing low levels (usually below 300 ng/dL) are often needed to confirm the diagnosis.

If another condition or medication is causing the problem, that should be addressed first. For example, losing weight, treating sleep apnea, or changing certain medications may restore healthy testosterone levels naturally.

Low testosterone in older men can have many causes — from normal ageing and chronic illness to medication effects and lifestyle habits. It is not always a simple part of getting older. Identifying the specific cause helps determine the safest and most effective treatment plan. For many men, improving overall health, sleep, and activity can raise testosterone levels without immediate need for replacement therapy. For others, especially those with confirmed hypogonadism, hormone therapy may become an option — but only after a full medical evaluation and careful consideration of risks and benefits.

 When Should Testosterone Replacement Therapy Be Considered?

Testosterone replacement therapy, often called TRT, is a medical treatment used to restore testosterone levels in men who have a proven deficiency. For older men, deciding when to start this therapy can be complex. Not every man with lower testosterone needs treatment. Understanding when TRT is appropriate helps men make safe, informed choices with their healthcare providers.

Understanding What “Low Testosterone” Really Means

As men age, testosterone levels naturally decrease. This gradual decline often begins after age 30 and continues throughout life. For most men, this is part of normal aging. However, for some, levels drop below the range needed for healthy body function, leading to symptoms such as fatigue, decreased muscle strength, low libido, or mood changes.

Doctors define low testosterone—also called hypogonadism—based on both blood test results and symptoms. The typical medical threshold for low total testosterone is around 300 nanograms per deciliter (ng/dL), but numbers alone do not tell the whole story. Some men with slightly higher levels may still experience symptoms, while others with lower levels might feel fine.

Because testosterone levels can vary from day to day, physicians usually perform two or more morning blood tests, taken before 10 a.m. when hormone levels are highest. These tests help confirm the diagnosis before considering treatment.

Step 1: Confirm That Symptoms Match the Test Results

Before recommending TRT, doctors must connect symptoms with lab results. Common symptoms of testosterone deficiency include:

• Low sex drive or erectile difficulties

• Unexplained fatigue or reduced motivation

• Loss of muscle or bone strength

• Increased body fat or weight gain

• Mood changes, such as irritability or mild depression

However, many of these symptoms can also result from other conditions such as poor sleep, thyroid issues, diabetes, obesity, or even certain medications. Therefore, TRT should not be started just because a man feels tired or his lab result is slightly low. The doctor’s job is to determine whether low testosterone is truly the cause of those problems.

Step 2: Rule Out Reversible or Underlying Causes

Sometimes, low testosterone happens because of temporary or treatable factors. These include:

• Obesity – Excess body fat can lower testosterone production. Losing weight often improves levels naturally.

• Sleep apnea – Interrupted sleep affects hormone production; treating apnea can restore testosterone.

• Certain medications – Steroids, opioids, or long-term pain medicines can suppress testosterone.

• Chronic illnesses – Kidney, liver, or pituitary disorders may disrupt hormone balance.

If one of these issues is found, the doctor will usually treat that condition first. Many men regain normal hormone levels without needing TRT once the underlying cause is corrected.

Step 3: Identify Candidates for TRT

Testosterone therapy may be considered for men who meet all of the following:

1. Consistently low testosterone levels confirmed on repeat testing.

2. Symptoms clearly linked to low hormone levels.

3. No medical reasons that make TRT unsafe.

Examples include men with long-standing hypogonadism due to testicular or pituitary problems, or older men whose testosterone has fallen well below normal and who experience strong symptoms affecting their quality of life.

For men with mild, age-related decline but no significant symptoms, doctors often recommend lifestyle changes first—such as improved diet, exercise, and sleep—before prescribing hormones.

Step 4: Exclude Those for Whom TRT Is Unsafe

TRT is not appropriate for everyone. Certain conditions make testosterone therapy risky, such as:

• Prostate or breast cancer (current or suspected)

• Severe heart failure or recent heart attack

• Untreated sleep apnea

• High red blood cell count (polycythemia)

In these cases, increasing testosterone could worsen the underlying problem. A full medical evaluation is essential to ensure it’s safe to proceed.

Step 5: Shared Decision-Making with the Doctor

Even when men meet the criteria, the decision to start TRT should involve shared decision-making between patient and doctor. The doctor will explain:

• The possible benefits, such as better libido, mood, or energy.

• The possible risks, such as blood thickening or prostate changes.

• The monitoring plan, which includes regular blood tests and physical exams.

This discussion helps each man weigh whether potential benefits outweigh the risks for his situation. Some men choose to try TRT for a few months to see if symptoms improve, while others prefer not to start long-term treatment.

Step 6: Diagnostic and Evaluation Process

Before therapy begins, the doctor may order several tests to look for causes and ensure safety:

• LH and FSH (pituitary hormones): To identify whether the problem lies in the testicles or the brain’s hormone control center.

• Prolactin: To check for pituitary gland issues.

• PSA (prostate-specific antigen): To rule out prostate disease before starting TRT.

• Blood count: To measure red blood cell levels.

Depending on the findings, the doctor might refer the patient to an endocrinologist or urologist for specialized care.

Testosterone replacement therapy should not be started based only on age or one blood test. It is meant for men with both low measured levels and clear symptoms that interfere with daily life. The process includes confirming the diagnosis, ruling out reversible causes, and ensuring that no serious health conditions make therapy unsafe.

Starting TRT is a significant decision that should be guided by careful medical evaluation and open discussion between doctor and patient. For many older men, this thoughtful, step-by-step approach ensures that treatment—if started—is both effective and safe.

What Are the Potential Benefits of Testosterone Replacement Therapy in Older Men?

Testosterone replacement therapy (TRT) is designed to restore testosterone levels in men who have a medically confirmed deficiency. In older men, testosterone levels naturally decline as part of aging, but sometimes this drop becomes large enough to cause real health and quality-of-life problems. When therapy is prescribed carefully and monitored by a doctor, it can offer several benefits. Still, results vary from one man to another, and improvements may depend on age, overall health, and how low the testosterone level was before treatment.

Improvement in Sexual Function and Libido

One of the most noticeable benefits of TRT is the improvement in sexual desire, or libido. Many older men with low testosterone report a reduced interest in sex and a decline in sexual activity. Clinical studies show that restoring testosterone to normal ranges often improves sexual thoughts, frequency of sexual activity, and overall satisfaction.

TRT can also help with erectile function, although it is not a direct treatment for erectile dysfunction (ED). Men whose ED is due to low testosterone may notice firmer erections, but those whose ED is caused by poor blood flow or nerve damage might not see much change. Doctors sometimes combine TRT with other ED treatments if needed.

For many men, a modest but meaningful improvement in sexual function can enhance self-confidence and emotional well-being.

Increased Energy and Reduced Fatigue

Low testosterone can cause persistent tiredness, lower motivation, and feelings of weakness. Testosterone plays a key role in energy metabolism and muscle maintenance. When levels are low, the body may use energy less efficiently, leading to fatigue.

After several weeks of therapy, some men notice that they feel more alert and less exhausted during the day. However, research shows that energy gains are usually moderate rather than dramatic. TRT should not be viewed as a cure for chronic fatigue or low mood unless testosterone deficiency is clearly contributing.

Doctors often remind patients that improved sleep, regular exercise, and balanced nutrition work together with TRT to support higher energy levels.

Preservation and Increase of Muscle Mass and Strength

Testosterone is essential for building and maintaining lean muscle. Low levels often lead to loss of muscle size (called sarcopenia) and a rise in body fat. This change can make physical activity more difficult and increase the risk of falls and injury.

TRT can help reverse some of this muscle loss. Studies have shown that men on testosterone therapy tend to gain lean body mass and improve muscle strength, particularly in the legs and upper body. Weight-bearing exercise further strengthens this effect.

That said, the increase is gradual and depends on consistent therapy, physical activity, and proper nutrition. TRT works best when combined with regular resistance training, such as lifting light weights or using resistance bands.

Reduction in Body Fat and Improvement in Metabolism

Testosterone influences how the body stores and uses fat. When levels are low, fat tends to accumulate, especially around the abdomen. TRT may help reduce body fat percentage and improve insulin sensitivity, which can support better blood-sugar control in men with prediabetes or type 2 diabetes.

Some men report a more “fit” body shape after several months of treatment. However, TRT is not a weight-loss program. The main goal is to restore hormonal balance, not to substitute for diet or exercise. Doctors often advise lifestyle changes alongside therapy for the best metabolic results.

Stronger Bones and Lower Risk of Fractures

Another important benefit of TRT is its positive effect on bone health. Testosterone stimulates bone-building cells and helps maintain bone mineral density. As men age, the risk of osteoporosis (weak or brittle bones) increases—especially when testosterone levels fall.

Research has shown that TRT can increase bone density in the spine and hips, reducing the risk of fractures. These improvements often appear gradually over a year or more of consistent treatment. Maintaining healthy bones not only prevents injury but also helps older men stay active and independent.

Possible Improvements in Mood and Cognitive Function

Many men with low testosterone describe feelings of sadness, irritability, or lack of motivation. Because testosterone interacts with certain brain receptors, low levels can affect mood and mental sharpness.

TRT may help improve mood, confidence, and concentration in some men. Studies suggest modest benefits for memory and attention, though results are mixed. It is important to understand that testosterone therapy is not a treatment for clinical depression or dementia. Instead, it can help men who experience emotional changes that are directly linked to hormonal deficiency.

Men who notice ongoing depression or anxiety should still seek mental-health support, as these conditions often require separate treatment.

Improved Quality of Life in Selected Men

For men who meet medical criteria for low testosterone, TRT can lead to a better sense of overall well-being. Improvements in sexual health, muscle strength, and energy can make daily life feel easier and more satisfying. Many men also describe better focus, confidence, and vitality.

However, these benefits are not guaranteed for everyone. Some men experience little change despite normalized testosterone levels. Individual response depends on age, underlying health problems, and personal lifestyle factors.

Setting Realistic Expectations

Doctors emphasize that testosterone therapy is not a “fountain of youth.” It does not stop aging or restore the body to how it was decades earlier. Instead, it helps relieve specific symptoms caused by low testosterone. Most benefits appear slowly, often taking several months to reach full effect.

Men should also be aware that TRT requires regular blood tests and medical follow-up to adjust dosage and monitor safety. A balanced approach—focusing on realistic goals, lifestyle habits, and open communication with a healthcare provider—gives the best chance for positive outcomes.

What Are the Risks and Side Effects of Testosterone Therapy?

Testosterone replacement therapy (TRT) can improve some symptoms of low testosterone, but it is not risk-free. Every man thinking about TRT—especially older men—should understand the possible side effects, safety concerns, and the need for regular monitoring. Knowing these risks helps you make a careful and informed choice with your healthcare provider.

Common Side Effects

Skin problems

Some men develop acne or oily skin soon after starting TRT. Testosterone increases oil production in the skin’s glands, which can clog pores. This side effect is usually mild but may require gentle skin-cleansing products or a change in the medication form.

Fluid retention (edema)

TRT may cause the body to keep extra salt and water. This can lead to swelling of the ankles or feet, known as edema. Most cases are mild, but men with heart failure, kidney disease, or high blood pressure need special care because fluid buildup can worsen these conditions.

Breast tenderness or enlargement (gynecomastia)

When testosterone levels rise, a small amount can convert to estrogen. This shift may cause breast tissue to grow or feel sore. Although not dangerous, it can be uncomfortable or distressing.

Mood and energy changes

Some men report mood swings, irritability, or increased energy at the start of therapy. These symptoms usually settle after hormone levels stabilize. However, any strong emotional change should be discussed with the prescribing doctor.

Blood-Related Risks

Increased red blood cells (polycythemia)

Testosterone stimulates the bone marrow to make more red blood cells. While this helps oxygen delivery, too many cells thicken the blood, raising the risk of blood clots, stroke, or heart attack. Doctors check blood counts—especially hematocrit—before treatment, at 3–6 months, and every year afterward. If levels get too high, the dose may be reduced, therapy paused, or the man may need to donate blood to thin it safely.

 Effects on cholesterol

Some forms of TRT may slightly reduce HDL (“good”) cholesterol. The change is small for most men but can be meaningful for those with existing heart disease or high cholesterol. Regular blood tests help track this effect.

Effects on the Prostate

Benign prostatic hyperplasia (BPH)

Testosterone can enlarge the prostate gland, especially in men who already have BPH. This may cause urinary symptoms such as slow flow, frequent urination at night, or trouble starting to pee. If symptoms worsen, the dose may need adjusting or treatment for BPH may be added.

Prostate cancer

Doctors avoid starting TRT in men with known or suspected prostate cancer. Although current studies show mixed results, testosterone may stimulate growth of existing cancer cells. For this reason, men over 40 usually have a prostate-specific antigen (PSA) blood test and sometimes a digital rectal exam before starting therapy. During treatment, PSA levels are rechecked every 6–12 months. A sudden rise in PSA or new prostate symptoms requires prompt medical review.

Cardiovascular and Respiratory Concerns

Heart and blood vessel risks

The link between TRT and heart disease is complex. Some studies suggest TRT may raise the risk of heart attack or stroke, especially in older men with pre-existing heart problems. Others show neutral or even beneficial effects on metabolism and fat distribution. Because the research is mixed, most experts recommend avoiding TRT in men who have had a recent heart attack, stroke, or severe heart failure. For others, careful monitoring—blood pressure, cholesterol, and heart function—is essential.

Sleep apnea

Testosterone can worsen obstructive sleep apnea, a condition in which breathing stops briefly during sleep. Symptoms include loud snoring, gasping at night, or feeling very tired during the day. Men who already have sleep apnea should be treated for it before starting TRT. Their doctors may also recommend sleep testing after therapy begins.

Fertility and Testicular Effects

TRT can lower sperm production by reducing signals from the brain that tell the testes to make sperm. In younger men who want children, this may cause infertility. Although many older men are not planning more children, it is still important to understand that TRT can shrink the testes and decrease sperm count. These changes may not fully reverse when therapy stops.

Other Potential Effects

• Hair loss: Higher testosterone levels can speed up male-pattern baldness in men who are genetically prone.

• Pain or irritation at the application site: Gels and patches may irritate the skin; injections can cause soreness or bruising.

• Accidental transfer: If using topical gel, it can rub off on others through skin contact. Washing hands and covering the area with clothing lowers this risk.

The Importance of Monitoring

Because these risks can develop slowly, regular medical follow-up is vital. Before starting TRT, most doctors order baseline tests:

• Testosterone levels (two morning samples)

• Hematocrit or hemoglobin (blood thickness)

• PSA and prostate exam

• Cholesterol and blood sugar

• Blood pressure and heart history

After starting TRT, repeat blood tests at 3 months, 6 months, and yearly help track any changes. If serious side effects appear—such as shortness of breath, chest pain, severe swelling, or very high red blood cell counts—therapy may be paused or stopped.

Balancing Benefits and Risks

For many older men, TRT can safely relieve symptoms when monitored closely. But ignoring possible side effects can cause harm. The safest path is shared decision-making: discuss your health history, goals, and concerns openly with your doctor. Together, you can weigh the benefits—like better mood, strength, or sexual function—against the risks described above.

Testosterone therapy can help some men feel stronger and more energetic, but it must be handled with care. It can thicken the blood, affect the prostate, and stress the heart or breathing in certain people. Regular testing and good communication with your healthcare team protect you from these risks and ensure that the treatment truly benefits your overall health.

How Is Testosterone Replacement Therapy Given, and What Are the Practical Considerations?

When a man is diagnosed with low testosterone and both he and his doctor decide that testosterone replacement therapy (TRT) is appropriate, the next question is how the hormone will be given. There is no single best method for every man. The choice depends on medical history, cost, comfort, and how easy it is to use the treatment safely over time. In older men, convenience, safety, and regular follow-up are especially important. Below are the main ways testosterone can be prescribed and what you should know about each.

Topical Testosterone Gels and Creams

These are among the most common ways to replace testosterone. They come in pump bottles, small packets, or tubes, and are usually applied once a day to clean, dry skin on the shoulders, upper arms, or abdomen. The testosterone is absorbed through the skin and enters the bloodstream slowly over 24 hours, keeping levels more stable.

Advantages:

• Easy and painless to use.

• Gives fairly steady testosterone levels compared to injections.

• Can be stopped easily if side effects appear.

Disadvantages and precautions:

• The hormone can transfer to others through skin contact. It’s important to wash hands after applying and cover the area with clothing once dry.

• Absorption can vary between individuals depending on skin type, sweating, or washing habits.

• Daily use is required, and missing applications can cause levels to fall.

• Usually more expensive over the long term than injections.

Older men who live with partners, grandchildren, or caregivers need to be especially careful to prevent accidental transfer. Washing or changing clothes after skin contact reduces this risk.

Testosterone Skin Patches

Transdermal patches are applied once daily, usually on the back, abdomen, thighs, or upper arms. They release testosterone gradually through the skin.

Advantages:

• Mimic the body’s natural daily rhythm of testosterone.

• Easy to apply at home.

• Avoid the peaks and valleys seen with injections.

Disadvantages:

• Skin irritation or rash is common at the patch site.

• The patch can loosen or fall off with sweating.

• Some men find the adhesive uncomfortable, especially with thin or sensitive skin.

Because older skin may be thinner and more fragile, patches are not always well tolerated in elderly men. Doctors may suggest rotating application sites to avoid skin problems.

Injectable Testosterone (Intramuscular or Subcutaneous)

Injections are another widely used option. Testosterone is given into a muscle (intramuscular) or under the skin (subcutaneous) using a syringe. The two main types are short-acting injections (every 1–2 weeks) and long-acting injections (every 10–12 weeks, depending on the formulation).

Advantages:

• Cost-effective and widely available.

• Dosing can be adjusted easily.

• Do not risk hormone transfer to others.

Disadvantages:

• Levels can fluctuate: they may be high right after an injection and low just before the next one. These ups and downs can cause mood or energy swings.

• Some men find injections painful or inconvenient, especially if they must visit a clinic for each dose.

• There is a small risk of bleeding, bruising, or infection at the injection site.

• Long-acting injections may need close observation for reactions during or after the shot.

Older men who take blood thinners or have reduced mobility may find injections less suitable unless they have reliable help with administration.

Testosterone Pellets (Implants)

Tiny pellets containing testosterone are placed under the skin, usually in the hip or buttock area, in a simple office procedure done under local anesthesia. The pellets slowly release testosterone for 3–6 months.

Advantages:

• Long duration—no need to remember daily or weekly doses.

• Stable testosterone levels without major peaks or dips.

• No risk of transfer to others.

Disadvantages:

• Requires a minor surgical procedure for insertion and removal.

• Possible bruising, infection, or pellet extrusion (working its way out).

• Not easily stopped if side effects occur.

Pellets can be convenient for older men who want to avoid frequent applications or injections, but they require careful monitoring and skilled insertion.

Buccal (Gum) Tablets and Nasal Gels

Less common forms include buccal tablets, which stick to the gum above the upper teeth, and nasal gels, which are applied inside the nostrils two to three times per day.

Advantages:

• Avoids skin transfer risk and injection pain.

• Provides steady absorption when used correctly.

Disadvantages:

• Buccal tablets can cause gum irritation or taste changes.

• Nasal gels need multiple daily doses and may not be tolerated by people with sinus problems.

• These methods are often more costly.

Choosing the Right Method

Selecting the best method depends on several factors:

• Lifestyle and convenience: Daily gels may not suit men who forget doses, while injections may be better for those who prefer less frequent treatment.

• Cost and insurance: Some forms are much more expensive and not always covered.

• Medical conditions: Men with skin disorders may not tolerate topical forms; those with needle phobia may avoid injections.

• Ability to self-manage: Fine motor skills, vision, and cognitive ability all affect whether an older man can safely use topical or injectable treatments.

• Monitoring needs: All methods require follow-up blood tests to ensure testosterone levels stay within the target range and to watch for side effects such as increased red blood cells or prostate changes.

Doctors often start with the form that best fits a patient’s daily routine and can be safely adjusted if needed. Whatever form is chosen, the goal is to restore testosterone to a normal range, relieve symptoms, and do so with the lowest possible risk.

Testosterone therapy is not “one size fits all.” Gels, patches, injections, pellets, and other forms each have benefits and drawbacks. Older men should work closely with their healthcare provider to choose a treatment they can use safely and consistently. Regular medical follow-up is essential to make sure the hormone level stays balanced, side effects are caught early, and the therapy truly improves quality of life.

What Monitoring and Follow-Up Are Needed During Testosterone Therapy?

Starting testosterone replacement therapy (TRT) is not a one-time decision. It is a long-term medical treatment that needs careful monitoring to make sure it is both safe and effective. Because testosterone affects many organs — including the heart, liver, blood, bones, and prostate — doctors check many things before and during treatment. Regular follow-up visits help ensure that testosterone levels stay in the healthy range and that any side effects are caught early.

Before Starting Therapy

Before TRT begins, your doctor will do a complete evaluation. This helps confirm that low testosterone is truly the cause of your symptoms and not another illness.

Confirming Low Testosterone

You’ll usually have at least two separate morning blood tests. Testosterone levels are highest in the morning, so testing before 10 a.m. gives the most accurate result. Each test checks total testosterone and sometimes “free testosterone,” which is the active form available to your body’s tissues. If both tests show low levels (commonly below 300 ng/dL) and you have matching symptoms such as fatigue, low sex drive, or loss of muscle, your doctor may consider TRT.

Finding the Cause

Your doctor might also measure other hormones such as LH (luteinizing hormone) and FSH (follicle-stimulating hormone). These help show whether the problem is in the testicles or in the brain’s pituitary gland. Sometimes, doctors also check prolactin, thyroid hormones, or order an MRI if a pituitary problem is suspected.

Checking General Health

Because testosterone interacts with many body systems, a baseline health review is important. This may include:

• Prostate check: a PSA (prostate-specific antigen) blood test and sometimes a digital rectal exam (DRE) to screen for prostate disease.

• Blood count: to measure red blood cells (hematocrit or hemoglobin). TRT can increase these levels, which may raise the risk of blood clots.

• Cholesterol and blood sugar tests: since testosterone can affect fat and sugar metabolism.

• Sleep apnea screening: if you snore heavily or feel unusually tired, because TRT can worsen untreated sleep apnea.

• Cardiovascular review: especially if you have heart disease, high blood pressure, or history of stroke.

If any of these tests show problems — for example, untreated prostate cancer, very high red blood cell count, or serious heart failure — TRT might be delayed or avoided.

During the First Months of Therapy

Once therapy begins, close observation helps find the right dose and delivery method for you. The first few months often involve more frequent blood tests and follow-ups.

Testosterone Levels

Your doctor will recheck your testosterone about 2–3 months after starting therapy. The goal is usually to keep your level in the mid-normal range for healthy younger men, roughly 400–700 ng/dL. Levels that are too high may raise risks, while levels that are too low mean the dose may need to be adjusted.

Blood Counts

Hematocrit and hemoglobin should be checked at the same visit. If they become too high (for example, hematocrit above 54%), your doctor might reduce your dose, pause treatment, or recommend donating blood to lower it. High hematocrit can increase the chance of stroke or heart attack.

Prostate Monitoring

PSA and prostate exams are often repeated at 3–6 months. If PSA rises quickly or your doctor finds abnormalities, further tests or a referral to a urologist may be needed. TRT should not cause large PSA jumps, but close tracking helps detect problems early.

Symptoms and Side Effects

Each visit is also a time to review how you feel. Some improvements — such as better energy or mood — can appear within weeks, while others, like stronger bones, take months or years.
Your doctor will ask about:

• Energy, sex drive, and mood changes

• Any acne, hair loss, or breast tenderness

• Swelling of ankles or legs (fluid retention)

• Trouble breathing or worsening sleep (possible sleep apnea)

• Increase in urination or difficulty starting urine (possible prostate effect)

It is helpful to keep a symptom diary between visits. This helps your doctor see patterns over time.

Long-Term Follow-Up

If everything looks good after the first few months, your doctor will usually continue to monitor you every 6–12 months. These check-ups make sure the therapy remains effective and safe.

At each visit, your care team may check:

• Testosterone level to ensure it stays in range.

• Hematocrit/hemoglobin to avoid dangerous thickening of blood.

• PSA and prostate health to detect any early warning signs of prostate issues.

• Cholesterol, liver function, and blood sugar to track overall metabolic health.

• Weight and blood pressure, since TRT can affect these.

• Bone density (every few years if you had osteoporosis before therapy).

Your doctor will also ask if you’ve noticed changes in your energy, mood, or body composition. If you are not feeling any improvement after 3–6 months, even with normal testosterone levels, continuing TRT may not be beneficial. Your doctor might then recommend stopping or reassessing other causes of your symptoms.

Why Consistent Monitoring Matters

Some men believe that once they start testosterone, they can “set it and forget it.” This is not true. Testosterone therapy can have real medical risks, especially in older men. Regular follow-up:

• Helps find the lowest effective dose, reducing side effects.

• Detects hidden problems early, such as rising PSA or thickened blood.

• Provides a chance to discuss how you actually feel, not just what your lab results show.

• Builds a long-term plan that keeps your quality of life and safety in balance.

Monitoring testosterone therapy is as important as the treatment itself. Before starting TRT, a detailed evaluation confirms the diagnosis and ensures safety. In the first few months, close testing helps adjust the dose. Over time, routine check-ups every 6–12 months protect your heart, prostate, and blood health. Always keep open communication with your healthcare provider and never skip follow-up visits. Proper monitoring allows you to gain the benefits of testosterone therapy while minimizing its risks — helping you stay healthy, active, and informed as you age.

When Testosterone Therapy May Not Be Appropriate—or Requires Extra Caution—in Older Men

Testosterone replacement therapy (TRT) can help some older men feel stronger, more energetic, and more sexually active. However, it is not suitable for everyone. In certain medical situations, TRT may be unsafe or may make an existing condition worse. Even when it is considered safe, doctors often use extra caution before starting treatment, especially in older men who may already have other health problems.
This section explains the main reasons why testosterone therapy might not be appropriate and why careful evaluation is important before beginning treatment.

Medical Conditions That Make Testosterone Therapy Unsafe

There are several health problems where TRT should not be used at all unless cleared by a specialist. These are known as contraindications—conditions that make a treatment unsafe or high-risk.

Prostate cancer

Men who have prostate cancer, or who are being treated for it, should not take testosterone. Testosterone can stimulate the growth of prostate tissue. If cancer cells are present, raising testosterone levels could make the cancer grow faster. For this reason, doctors always check the prostate before starting therapy. This may include a digital rectal exam (DRE) and a prostate-specific antigen (PSA) blood test. If either test raises concern, further evaluation is needed before TRT is considered.

Breast cancer in men

Although rare, men can develop breast cancer. Because testosterone may be converted to estrogen in the body, it can affect breast tissue. Men with a current or past history of breast cancer should avoid TRT.

Untreated severe sleep apnea

Sleep apnea is a condition where breathing stops and starts during sleep. Testosterone can sometimes make sleep apnea worse by relaxing airway muscles. In men who already have severe, untreated sleep apnea, TRT can increase the number of breathing pauses and lower oxygen levels at night. Doctors often require that sleep apnea be treated—usually with a CPAP machine—before starting testosterone.

Uncontrolled heart failure or recent heart attack/stroke

Testosterone can cause the body to retain salt and water, which can increase swelling and worsen heart failure. If a man has uncontrolled heart failure, TRT is not recommended. There is also concern about possible cardiovascular risks. While research is mixed, doctors usually delay or avoid testosterone treatment in men who have had a heart attack, stroke, or major cardiac event within the past few months.

Very high red blood cell count (polycythemia)

Testosterone stimulates the bone marrow to make red blood cells. In some men, this can cause polycythemia, a condition where blood becomes thicker and flows more slowly. This raises the risk of blood clots, stroke, or heart attack. If blood tests show that the hematocrit (the percentage of red blood cells in blood) is above the safe limit—typically above 52%—TRT should be stopped or avoided until corrected.

Men planning to have children

Although this concern is more common in younger men, it is worth noting that testosterone therapy can reduce sperm production and fertility. For older men still planning fatherhood, TRT should not be started. Testosterone signals the brain to slow down the natural hormone signals that make sperm.

Conditions That Require Extra Caution

There are other conditions that do not completely rule out TRT but require careful monitoring.

Benign prostatic hyperplasia (BPH)

BPH is an enlargement of the prostate that causes urinary symptoms such as weak flow or frequent urination. Testosterone can worsen these symptoms in some men. Therefore, doctors often monitor urinary function closely and may avoid TRT if symptoms are severe.

Elevated PSA or prostate concerns without cancer diagnosis

Even if prostate cancer is not confirmed, a rising PSA level or an abnormal DRE finding may prompt doctors to delay TRT until the cause is clarified. Safety always takes priority.

Mild or moderate sleep apnea

Men with mild sleep apnea may still use TRT under medical supervision. The doctor will often recommend a sleep study and regular follow-up to ensure the condition does not worsen.

Men with high cardiovascular risk

Older men often have several cardiovascular risk factors—high blood pressure, diabetes, or high cholesterol. These do not automatically exclude TRT, but they mean closer follow-up is needed. Regular monitoring of heart health, blood pressure, and cholesterol helps reduce risk.

The Debate About Age-Related Testosterone Decline

One of the most difficult decisions for doctors is whether to prescribe testosterone for “age-related” low testosterone—that is, men who do not have a disease causing their low levels, but whose testosterone has naturally decreased with age. Some men in this group feel tired, depressed, or have reduced sexual desire. While TRT may improve some of these symptoms, large studies show mixed results. The benefits may be small, and the risks (especially for prostate and heart health) are still being studied.

Most medical guidelines—including those from the Endocrine Society—recommend not prescribing TRT routinely for healthy older men with only age-related declines. Instead, they suggest focusing on managing lifestyle factors such as weight, exercise, sleep, and other health conditions before starting therapy. If symptoms remain troublesome and low testosterone is confirmed, doctors may consider a time-limited trial of TRT, but always with informed consent and regular follow-up.

The Importance of Individualized Decision-Making

Because every man’s health situation is different, the decision to start testosterone therapy should always be personalized.
Before prescribing TRT, a doctor should:

• Take a complete medical history and physical exam.

• Perform appropriate lab tests (including testosterone levels, PSA, and hematocrit).

• Discuss the possible benefits, risks, and uncertainties.

• Make sure any serious health problems are under control.

Older men with several chronic illnesses may still benefit from TRT if used carefully, but only after a risk-benefit discussion and with close monitoring. Follow-up visits are essential to check for improvements and side effects.

Testosterone therapy can be a helpful treatment for carefully selected men, but it is not safe for everyone. It should be avoided in men with prostate or breast cancer, untreated severe sleep apnea, uncontrolled heart disease, or high red blood cell counts. It must be used carefully in men with prostate enlargement, cardiovascular risk, or mild sleep apnea. For age-related low testosterone, treatment decisions should be made on a case-by-case basis, with full understanding of both the benefits and the uncertainties.

What Is the Evidence for Long-Term Outcomes of Testosterone Therapy in Older Men?

Understanding what happens when older men take testosterone replacement therapy (TRT) for many years is one of the most important and most debated questions in medicine today. While short-term studies show some benefits, long-term data are still limited. Scientists continue to study how TRT affects the body over time, especially in older men who may already have other health problems. Below is a clear summary of what we know so far about the long-term outcomes of testosterone therapy.

Benefits Seen in Long-Term Studies

Several studies have shown that testosterone therapy can help men with proven low testosterone feel better and improve some aspects of their health.

Sexual Function and Libido

One of the most consistent long-term benefits of TRT is better sexual function. Older men often report stronger sexual desire and more frequent sexual activity. Studies from the Testosterone Trials (TTrials) — a large, government-funded group of clinical studies in the United States — found that men over 65 who took testosterone gel for one year experienced modest but meaningful improvements in sexual interest and activity. These effects tended to appear within a few months and were maintained over time as long as testosterone levels stayed in the normal range.

Muscle Mass and Strength

Long-term TRT has been linked to increased muscle mass and a small but noticeable improvement in strength. This is important because many older men lose muscle as they age, which can lead to weakness and falls. Testosterone seems to stimulate muscle protein synthesis, helping maintain lean body mass. However, most studies show that the greatest benefits occur in the first year, and gains level off afterward unless combined with exercise and good nutrition.

Bone Density and Fracture Risk

Bone loss (osteoporosis) becomes more common with age, and testosterone plays a role in keeping bones strong. Research shows that after one to two years of TRT, bone mineral density — especially in the spine and hip — improves in men with low testosterone. The TTrials’ Bone Trial arm found stronger bones after one year of treatment, suggesting long-term therapy could reduce fracture risk. However, it is not yet proven whether TRT actually prevents bone fractures in older men.

Risks and Safety Concerns in Long-Term Use

Cardiovascular Health

The effect of testosterone therapy on the heart and blood vessels has been the focus of much research and debate. Some older studies suggested an increased risk of heart attack or stroke, especially in older men or those with pre-existing heart disease. However, more recent large trials, such as the 2023 TRAVERSE trial, found no increase in major cardiovascular events among men treated with testosterone for several years compared with placebo. Still, most experts agree that TRT should be used cautiously in men with a history of heart disease, and patients should be monitored regularly for blood pressure, cholesterol, and heart symptoms.

Prostate Health

Another common concern is whether testosterone therapy increases the risk of prostate cancer. So far, long-term studies do not show that TRT causes prostate cancer. Testosterone can, however, cause prostate tissue to grow slightly, which may worsen symptoms of benign prostatic hyperplasia (BPH), such as difficulty urinating. Men on TRT should have their prostate-specific antigen (PSA) levels and prostate exams monitored regularly to detect any abnormal changes early.

Blood Thickening (Polycythemia)

Testosterone therapy can increase red blood cell production. While this can improve energy in men with low hemoglobin, it can also make the blood too thick, raising the risk of blood clots. This effect is more common in older men and in those using injectable forms of testosterone. Regular blood tests to measure hematocrit and hemoglobin are essential, and if levels become too high, treatment may need to be paused or the dose lowered.

Sleep Apnea and Fluid Retention

TRT may worsen sleep apnea, a condition in which breathing stops briefly during sleep. It can also cause mild swelling of the ankles due to fluid retention. These side effects are usually manageable with medical supervision but highlight why older men must be carefully screened before and during treatment.

How Guidelines Interpret the Evidence

Professional medical societies have carefully reviewed the evidence and reached cautious conclusions.

• The Endocrine Society recommends TRT only for men with symptoms and consistently low testosterone levels confirmed by blood tests.

• The American College of Physicians (ACP) advises offering testosterone mainly to improve sexual function in older men, not for general fatigue or mood issues, since evidence for those effects is weaker.

• Both groups stress that doctors and patients should discuss potential benefits and risks and make decisions together.

What We Still Do Not Know

Although TRT has been available for decades, we still lack large, long-term (10+ year) studies that clearly show its effects on overall survival, dementia, or chronic disease risk. More research is needed to understand:

• How TRT affects men with multiple health conditions such as diabetes or obesity

• Whether it helps prevent frailty or cognitive decline

• The best duration of therapy for older men

So far, data suggest that when used appropriately and monitored carefully, testosterone therapy can be safe and helpful for some men, but not all.

The Importance of Individualized Care

Because older men often have other health conditions, testosterone therapy should never be started lightly. Each man’s case is unique. A full medical evaluation — including hormone tests, heart and prostate assessments, and review of medications — is essential before beginning treatment. Regular follow-up visits help ensure the benefits outweigh the risks.

The long-term evidence for testosterone therapy in older men shows real but moderate benefits for sexual function, muscle mass, and bone health. The risks — especially to the heart, blood, and prostate — require careful monitoring. Decisions about treatment should be made jointly between patient and doctor, using up-to-date information and regular testing to ensure safety over time.

Conclusion

Low testosterone is a common concern for many older men. As men age, it is normal for testosterone levels to slowly decrease. However, when this drop leads to symptoms such as fatigue, low sex drive, loss of muscle, mood changes, or bone weakness, it may be more than normal ageing—it could be a medical condition called testosterone deficiency or hypogonadism. The key message is that not all low testosterone levels require treatment. The decision to start testosterone replacement therapy (TRT) should be thoughtful, evidence-based, and made together with a qualified healthcare professional.

Before starting treatment, a doctor will first make sure the testosterone level is truly low. Because testosterone levels can vary from day to day, it’s important to test them in the morning, when they are usually highest, and to confirm with at least two separate blood tests. A doctor will also review symptoms and rule out other causes, such as obesity, stress, poor sleep, medications, or chronic illnesses that can also affect hormone levels. Only when low testosterone is confirmed and linked with clear symptoms should TRT be considered.

For men who meet these criteria, testosterone therapy can offer certain benefits. Some men experience improved sexual desire, better erectile function, and a stronger sense of well-being. In others, TRT may help increase muscle mass, reduce fat, and protect bone density. These effects, however, can vary. The benefits are usually greater in men with significantly low testosterone levels than in those with only mildly reduced levels. It’s important for older men to have realistic expectations. Testosterone therapy does not reverse ageing or act as a general energy booster for everyone. Instead, it works best when used to treat specific symptoms caused by a true deficiency.

Alongside potential benefits, TRT comes with risks that must be carefully weighed. Side effects can include acne, oily skin, breast enlargement, or swelling in the legs from fluid retention. It can increase the number of red blood cells in the blood, which can raise the risk of blood clots or stroke if not monitored. Some men may notice worsening of sleep apnea or an increase in prostate size, which can cause urinary problems. Because testosterone may stimulate growth in the prostate, men must have their prostate checked before and during therapy, even though current evidence does not show that TRT causes prostate cancer. The balance of benefit and risk depends on each man’s overall health, age, and other medical conditions.

Monitoring is a vital part of safe testosterone therapy. Before starting treatment, a doctor will usually check testosterone levels, red blood cell counts, prostate-specific antigen (PSA), and other health measures. Once therapy begins, these tests are repeated regularly—usually every 3 to 6 months during the first year—to ensure that levels remain within a healthy range and to catch any early side effects. If no improvement in symptoms occurs after several months, or if risks start to outweigh benefits, it may be best to stop treatment. Testosterone replacement is not a “set it and forget it” therapy; it needs regular review and adjustment.

Not every man is a good candidate for testosterone therapy. It is generally not recommended for men with untreated prostate or breast cancer, severe heart failure, or high red blood cell counts. It should also be avoided in men who have recently had a heart attack or stroke until they recover and their doctor advises it is safe. Some men may have symptoms that resemble low testosterone but are actually caused by lifestyle factors such as poor sleep, lack of exercise, excessive alcohol use, or obesity. In these cases, improving overall health may raise testosterone levels naturally without the need for medication.

Long-term studies on testosterone therapy in older men are still ongoing. So far, evidence suggests that TRT can safely improve sexual function and bone health in men with true deficiency, but questions remain about long-term effects on heart disease, memory, and lifespan. Because of these uncertainties, medical organizations recommend shared decision-making. This means the doctor and patient should openly discuss the possible benefits, the known and unknown risks, and the patient’s goals and values. There is no “one-size-fits-all” answer; what is right for one man may not be right for another.

In the end, testosterone therapy should be viewed as a medical treatment, not an anti-ageing shortcut. When used appropriately, it can greatly improve quality of life for men who have genuine low testosterone and troubling symptoms. But it must be prescribed carefully, monitored closely, and reviewed often. The safest approach is to work with a doctor—usually an endocrinologist or urologist—who has experience managing hormone therapy in older men. Together, the patient and doctor can decide if testosterone therapy is necessary, start at the right dose, and keep track of both benefits and side effects over time.

For men wondering whether low testosterone might be affecting their health, the best first step is to talk with a healthcare professional. An honest discussion, proper testing, and a full review of symptoms can help determine the right course of action. Testosterone therapy can help some older men feel better and stronger, but it should always be used with care, attention, and medical guidance. Informed choices and ongoing medical supervision are the keys to using hormone replacement safely and effectively as men age.