Testosterone Therapy for Men: Benefits, Risks, and Its Impact on Prostate Health

Introduction

Testosterone is one of the most important hormones in the male body. It influences how a man looks, feels, and functions each day. Testosterone plays a role in building muscle and bone strength, maintaining sexual desire, supporting sperm production, and helping with mood and energy levels. While testosterone levels are usually highest in adolescence and early adulthood, they naturally decline as men age. This gradual decrease is normal, but for some men, levels fall low enough to cause symptoms that affect daily life. These symptoms can include reduced sexual desire, difficulty with erections, fatigue, loss of muscle strength, increased body fat, depressed mood, and problems with concentration. When these symptoms are paired with lab tests showing low testosterone levels, a doctor may diagnose a condition called low testosterone or testosterone deficiency.

To address this condition, some men consider testosterone therapy. Testosterone therapy, often called TRT, is a medical treatment that raises testosterone levels in the body to a healthier range. It can help improve physical, emotional, and sexual well-being in men who truly have low testosterone. The goal of TRT is not to raise testosterone higher than normal, but to restore it to the level that supports normal function. When prescribed and monitored by a healthcare professional, testosterone therapy can significantly improve quality of life for men experiencing symptoms of deficiency.

However, many men have questions about how testosterone therapy interacts with prostate health. The prostate is a small gland in the male reproductive system that helps produce semen. It is located just below the bladder and surrounds part of the urethra, the tube that carries urine out of the body. Because the prostate is influenced by testosterone, the relationship between testosterone levels and prostate changes has been studied for many decades. Historically, there were concerns that increasing testosterone might cause the prostate to enlarge or increase the risk of prostate cancer. These concerns led to caution in using testosterone therapy for many years.

As medical research has improved, our understanding of testosterone and prostate health has grown more detailed and more accurate. Current scientific evidence does not show that testosterone therapy causes prostate cancer. However, this does not mean that prostate health can be ignored. The prostate can still respond to hormone changes, and in some men, symptoms such as urinary frequency or difficulty urinating may become more noticeable. These symptoms are commonly linked to benign prostatic hyperplasia (BPH), a condition in which the prostate becomes larger as men age. Because BPH and prostate cancer can occur in older men, and because TRT is often used later in life, proper medical monitoring is essential.

Understanding these connections helps men make informed decisions. Testosterone therapy has real benefits for those who need it, but it is not a casual treatment. Not every man with low energy or stress needs testosterone therapy, and the therapy is not the same as taking supplements or performance-enhancing drugs. It is a prescription medical treatment that requires careful testing, follow-up blood work, and ongoing evaluation of symptoms and overall health. Doctors usually perform prostate screening before starting therapy to look for any signs of prostate disease. During treatment, healthcare professionals continue to check testosterone levels, prostate-specific antigen (PSA) levels, and other markers to make sure the therapy remains safe.

The purpose of this article is to clearly explain testosterone therapy, the benefits it may offer, the risks that are known, and what research says about its relationship to prostate health. The goal is to provide information that is easy to understand and based on current medical evidence. This article will explain who may benefit from testosterone therapy, how it is given, what changes to expect, and how prostate health should be monitored during treatment. It will also discuss common questions and concerns that men often have when deciding whether testosterone therapy is right for them. By understanding the science, the risks, and the benefits, men can work with their healthcare providers to make informed, confident decisions about their health.

What Is Testosterone and Why Is It Important?

Testosterone is a hormone that plays a central role in men’s health. It is produced mainly in the testicles and to a smaller extent in the adrenal glands. Although both men and women have testosterone, men have much higher levels. Testosterone affects many parts of the body, not just reproductive health. It influences physical strength, energy levels, mood, metabolism, and even how the body stores fat. Because testosterone affects so many systems, having the right balance is important for well-being.

Testosterone’s Role in the Body

Testosterone has several key functions:

• Sexual and Reproductive Health:
  Testosterone supports sex drive (libido), helps maintain healthy erectile function, and plays a role in sperm production. When testosterone levels are low, men may notice a reduced interest in sexual activity, difficulty maintaining erections, or lower fertility due to reduced sperm count.

• Muscle and Bone Strength:
  Testosterone supports muscle growth by helping the body build and maintain muscle protein. It also helps keep bones dense and strong. Lower testosterone can lead to reduced muscle tone, decreased physical strength, and increased risk of bone thinning (osteoporosis) over time.

• Body Fat and Metabolism:
  Testosterone affects how the body stores and burns fat. With low levels, men may gain weight more easily, especially in the belly area. Changes in metabolism may also contribute to fatigue and low energy.

• Mood, Energy, and Cognitive Function:
  Testosterone interacts with brain chemicals involved in mood and focus. Men with low levels sometimes report feeling tired, sad, irritable, or unfocused. While testosterone is not a cure for depression, hormone imbalance can contribute to emotional and mental changes.

• Red Blood Cell Production:
  Testosterone helps stimulate the bone marrow to make red blood cells. Very low levels may lead to low red blood cell counts, while high testosterone levels from therapy without monitoring can cause too many red blood cells, which can increase health risks. This is why medical supervision is important when treating low testosterone.

How Testosterone Levels Change With Age

Testosterone levels naturally peak during late adolescence and early adulthood. After about age 30, most men experience a slow and steady decline. This decrease is normal and part of aging. However, some men experience a more significant drop in testosterone levels, leading to noticeable symptoms that affect daily life.

Symptoms of Low Testosterone

The symptoms of low testosterone (sometimes called “low T” or hypogonadism) may develop gradually. Common symptoms include:

• Reduced sex drive

• Difficulty with erections

• Fatigue or low energy

• Reduced muscle mass and physical strength

• Increased body fat, especially around the abdomen

• Changes in mood (irritability, sadness, or low confidence)

• Difficulty concentrating or remembering things

• Reduced body or facial hair growth

These symptoms can also be caused by other health conditions, so hormone testing and medical evaluation are needed to confirm whether testosterone is the cause.

How Low Testosterone Is Diagnosed

Low testosterone is diagnosed through blood tests. Typically, testosterone levels are measured early in the morning, when levels are highest. If the result is low, doctors often repeat the test to confirm accuracy. A diagnosis is made only when both symptoms and persistently low hormone levels are present.

This step is important, because some men may have low readings without symptoms and may not need treatment.

Low Testosterone vs. Normal Aging

Some changes in energy, strength, and sexual function are part of normal aging. However, when testosterone levels fall below the expected range for age and symptoms are noticeable, treatment may be considered. The key difference is impact on daily life. If the decline in testosterone is significant enough to cause discomfort or reduced quality of life, medical evaluation is appropriate.

Why Understanding Testosterone Is Important

Testosterone therapy is becoming more common, but it should not be used casually. Understanding what testosterone does helps men make informed decisions about their health. Knowing the symptoms, testing process, and effects on the body allows men to recognize when medical evaluation is needed.

What Is Testosterone Therapy and Who Is It For?

Testosterone therapy, often called testosterone replacement therapy (TRT), is a medical treatment used to raise testosterone levels in men who have clinically low levels of this hormone. Testosterone is important for many body functions, including sexual health, muscle strength, energy, mood, and bone health. When levels become too low, men may experience symptoms that affect their daily life and overall well-being. TRT is used to help restore testosterone to a healthier range so the body can function more normally.

Understanding Low Testosterone (Hypogonadism)

Low testosterone, also called hypogonadism, refers to a condition where the body does not produce enough testosterone. This may happen because of aging, medical conditions, or problems with the testes or the parts of the brain that control hormone production.

Common signs and symptoms of low testosterone may include:

• Decreased sexual desire or interest

• Erectile dysfunction or difficulty maintaining erections

• Fatigue or low energy

• Loss of muscle mass or increased body fat

• Mood changes such as irritability or sadness

• Difficulty concentrating

• Reduced strength or stamina

• Decreased body hair growth

Not every man with these symptoms has low testosterone. Some symptoms overlap with other health conditions, stress, or aging. Because of this, proper medical testing is required.

How Low Testosterone Is Diagnosed

A diagnosis of low testosterone is based on both symptoms and blood test results. Most guidelines recommend:

1. Morning blood tests, because testosterone levels change throughout the day and are highest in the morning.

2. Two separate test results, taken on different days, to confirm the level is consistently low.

3. Evaluation of symptoms, medical history, and overall health.

Doctors also check other hormones to understand why testosterone is low and whether the issue is from the testes or the brain’s hormonal control centers.

Who May Benefit From Testosterone Therapy

Testosterone therapy is generally recommended for men who:

• Have symptoms of low testosterone, and

• Have consistently low blood testosterone levels confirmed by testing

Men who may benefit often include those with:

• Age-related decline in testosterone affecting quality of life

• Testicular damage from injury, infection, or chemotherapy

• Genetic or medical conditions affecting hormone production

• Pituitary gland or hypothalamus disorders

For these men, TRT may help improve energy, sexual function, mood, strength, and overall health.

Who Should Not Use Testosterone Therapy

There are situations where testosterone therapy is not recommended, because it may cause harm or make certain conditions worse. TRT may not be appropriate for:

• Men with prostate cancer or suspected prostate cancer

• Men with breast cancer (although rare in men, it can occur)

• Men with moderate to severe benign prostatic hyperplasia (BPH) or urinary obstruction

• Men with untreated severe sleep apnea

• Men with high red blood cell counts, which increases blood clot risk

• Men planning to have children, because TRT can lower sperm production and may cause infertility

Because TRT can affect several body systems, a complete medical evaluation is important before starting treatment.

Treatment Goals

The main goals of testosterone therapy are to:

• Reduce or relieve symptoms of low testosterone

• Restore testosterone to a healthy range

• Improve quality of life, sexual function, mood, and energy

• Support physical health such as muscle and bone strength

Doctors work with patients to choose a dose and form of testosterone that balances effectiveness with safety.

The Importance of Medical Supervision

Testosterone therapy should always be done under medical supervision. It is not the same as using testosterone or anabolic steroids for bodybuilding. Medical TRT requires:

• Regular blood tests to check hormone levels

• Monitoring prostate health and PSA levels

• Checking red blood cell counts

• Evaluating symptom improvement and side effects

This monitoring ensures the therapy is both effective and safe over time.

Forms of Testosterone Therapy and How They Are Administered

Testosterone therapy is available in several different forms. Each method delivers testosterone into the body in its own way, and each has certain advantages and disadvantages. Understanding how each form works can help men and their healthcare providers choose the option that best fits their needs, health goals, and lifestyle. This section explains the most common forms of testosterone therapy, how they are used, and what to consider when deciding between them.

Injectable Testosterone

Injectable testosterone is one of the most widely used forms of therapy. It is given as an injection into a muscle, often the thigh or buttock.

There are two main types of injectable testosterone:

1. Short-acting injections (e.g., testosterone cypionate or enanthate)
   • These are usually given every 1 to 2 weeks.

   • Testosterone levels tend to rise soon after the injection and then slowly fall before the next dose.

   • Because of this cycle, some men may feel a difference in how they feel during the week—such as more energy or better mood right after the injection, and lower energy as levels drop before the next one.

2. Long-acting injections (e.g., testosterone undecanoate)
   • These injections last longer and are usually given every 10 to 12 weeks in a medical office.

   • They keep testosterone levels more stable over time.

   • However, they must be administered by a healthcare professional, which may limit convenience.

Pros of injectable testosterone:

• Usually lower cost than other forms.

• Reliable absorption into the body.

Cons:

• May cause fluctuating hormone levels with short-acting forms.

• Some men may find injections uncomfortable or inconvenient.

• Requires proper technique if self-injecting at home.

Transdermal Gels and Patches

These forms deliver testosterone through the skin and into the bloodstream.

Gels

• Applied once daily, usually to the shoulders, upper arms, or abdomen.

• The skin absorbs testosterone slowly throughout the day, which helps maintain more stable hormone levels.

• It is important to let the gel dry before dressing to avoid rubbing it off.

• Men must also avoid skin-to-skin contact with others, especially women and children, until the gel is fully absorbed. This prevents accidental transfer of testosterone.

Patches

• Applied to the skin once daily, often on the back, abdomen, thigh, or upper arm.

• Patches deliver controlled and stable testosterone levels throughout the day.

• Some men may develop skin irritation from the adhesive patch.

Pros of gels and patches:

• Easy to use.

• Maintain stable levels without large peaks and drops.

Cons:

• More expensive than injections.

• Risk of accidental transfer of gel to others.

• Skin irritation may occur.

Testosterone Pellets (Subcutaneous Implants)

Pellets are inserted just under the skin, usually in the hip or buttock area, during a minor office procedure. The pellets slowly release testosterone for about 3 to 6 months.

Pros:

• Long-lasting and convenient—no daily or weekly dosing.

• Provides steady testosterone levels.

Cons:

• Requires a minor surgical procedure for placement and removal.

• Dose adjustments cannot be made easily once pellets are inserted.

• Risk of pellet shifting or coming out of the insertion site.

Oral and Buccal Testosterone

Oral forms of testosterone exist, but older versions were not safe for long-term use because they could harm the liver. Newer oral forms avoid the liver and are safer, but they may still be less commonly used.

There are also buccal tablets, which are placed between the gums and cheek. These slowly release testosterone into the bloodstream.

Pros:

• Easy to take without injections or skin applications.

Cons:

• Must be taken every day or multiple times per day.

• Some men experience gum irritation.

• Can be more expensive.

Choosing the Right Form of Therapy

The best form of testosterone therapy depends on several factors, including:

• Lifestyle and convenience (e.g., daily gel vs. infrequent pellets)

• Comfort with injections

• Cost and insurance coverage

• Medical conditions and treatment goals

• How steady testosterone levels need to be

A healthcare provider helps monitor testosterone levels, adjust dosing, and check for side effects. Regular follow-up is important, no matter which form is used.

Testosterone therapy can be given through injections, skin applications, implanted pellets, or oral/buccal forms. Each method works well, but they differ in convenience, cost, and the stability of testosterone levels they produce. Understanding these differences helps men and their healthcare providers make informed, personalized decisions about treatment.

What Are the Expected Benefits of Testosterone Therapy?

Testosterone therapy can help men who have been medically diagnosed with low testosterone levels and are experiencing symptoms that affect daily life. The benefits of therapy often develop gradually over weeks to months. The degree of improvement depends on the person’s baseline hormone levels, general health, age, and how consistently the treatment plan is followed. Below are the major areas where positive changes are commonly observed, supported by clinical research and long-term medical practice.

Improvement in Sexual Function and Libido

One of the most well-known benefits of testosterone therapy is its effect on sexual health. Testosterone plays an important role in sexual desire (also called libido), erectile function, and overall sexual satisfaction. Men with low testosterone may notice a reduced interest in sexual activity, difficulty starting or maintaining erections, or slower response to sexual stimulation.

Testosterone therapy does not work like medications for erectile dysfunction, which act directly on blood flow. Instead, testosterone supports sexual desire and the brain pathways that help trigger sexual arousal. With increased testosterone levels, many men report:

• A stronger interest in sex

• More frequent or spontaneous erections

• Improved satisfaction during sexual activity

• Increased confidence related to sexual performance

However, the response varies. Some men may notice improvements within a few weeks, while others may require several months. If erectile problems continue even after testosterone levels return to normal, additional assessment is often needed to look for vascular (blood flow), psychological, or other hormonal factors.

Increases in Muscle Mass and Strength

Testosterone is a building hormone. It helps maintain muscle tissue and supports protein synthesis, which is the process the body uses to repair and grow muscle fibers. Men with low testosterone may notice muscle loss, reduced strength, or difficulty maintaining muscle tone even when exercising.

With therapy, muscle mass usually increases gradually over several months, especially when combined with:

• Strength or resistance-based exercise

• Adequate protein intake

• A balanced and nutrient-rich diet

The increase in muscle strength can improve mobility, endurance, and stability. It may also help reduce the risk of falls or injuries, especially in older men.

Improved Bone Density

Testosterone is important for bone health. It helps maintain bone mineral density and reduces the risk of thinning bones (osteoporosis). Low testosterone can weaken bone tissue, making bones more likely to fracture, particularly in older men.

Testosterone therapy can:

• Slow or stop bone loss

• Gradually increase bone density over one to two years

• Reduce the risk of fractures in men with severe deficiency

The process is slow because bone rebuilding takes time. Improving bone health is often considered a long-term benefit of testosterone therapy.

Changes in Mood, Energy, and Cognitive Function

Many men with low testosterone describe feeling tired, unmotivated, or emotionally flat. Some also report difficulty focusing or remembering things. These symptoms are linked to how testosterone affects the brain and energy balance.

Testosterone therapy may help improve:

• Energy levels: Reduced fatigue and increased daily stamina

• Mood stability: Less irritability or mood swings

• Sense of well-being: A general improvement in outlook and confidence

• Mental clarity: Better focus and concentration in daily tasks

The effects can vary and are usually more noticeable when combined with lifestyle support such as quality sleep, exercise, and balanced nutrition. These improvements often occur gradually and may take several weeks to become clear.

Metabolic Effects

Testosterone also plays a role in metabolism, including how the body stores and uses fat. Low testosterone is associated with:

• Increased body fat, especially around the waist

• Reduced insulin sensitivity

• Higher risk of developing metabolic syndrome or type 2 diabetes

With therapy, many men experience:

• A decrease in abdominal fat

• Improved insulin sensitivity

• Better blood sugar regulation

• Potential improvements in cholesterol levels

These changes support heart and metabolic health over time but are most effective when paired with regular physical activity and healthy eating habits.

Testosterone therapy can provide broad physical and emotional health benefits when prescribed for true testosterone deficiency. These benefits include improved sexual function, increased muscle mass, stronger bones, better mood and energy levels, and positive effects on metabolism. Results take time and may require lifestyle support to reach full potential. Regular medical monitoring is essential to ensure safety and long-term effectiveness.

What Are the Potential Risks and Side Effects of Testosterone Therapy?

Testosterone therapy can provide meaningful health benefits for many men with confirmed low testosterone levels. However, like any medical treatment, it also has possible risks and side effects. Understanding these effects helps men and their healthcare providers make informed decisions and monitor treatment safely. Not every man will experience side effects, and some effects are avoidable or manageable with proper dosing and medical monitoring. Below are the major potential risks explained in clear, practical terms.

Erythrocytosis (Increase in Red Blood Cell Count)

One of the most common side effects of testosterone therapy is erythrocytosis, which means the number of red blood cells in the blood becomes too high. Testosterone can stimulate the bone marrow to produce more red blood cells. While some increase is expected and can even improve energy levels, too much can lead to thickened blood.

When blood becomes thicker than normal, it may increase the risk of blood clots, which can affect circulation in the legs, lungs, or brain. Regular blood tests can detect this early. If the red blood cell count becomes too high, the healthcare provider may adjust the dose, temporarily pause therapy, or recommend donating blood to reduce the level.

Acne, Oilier Skin, and Hair Changes

Because testosterone influences oil production in the skin, some men may notice:

• Oily skin

• Acne, especially on the shoulders, back, or face

• Hair thinning in men already prone to male-pattern baldness

These effects may be mild or temporary. Skincare routines and dose adjustments can help. Hair thinning is more likely if a man has a genetic tendency for it, rather than being caused directly by testosterone alone.

Water Retention and Swelling

Some men may retain more water while on therapy. This may appear as mild swelling in the ankles or feet. In most cases, this is not severe and may lessen after the body adjusts to treatment. However, men with kidney, heart, or liver conditions should be monitored more closely, as fluid balance is important in these conditions.

Effects on Fertility and Sperm Production

One of the most important effects of testosterone therapy is its impact on fertility. When testosterone is given from outside the body, the brain may reduce its own signal to the testes. As a result, the testes may produce less testosterone and fewer sperm. This can lower sperm count and affect the ability to have biological children.

For men who wish to remain fertile, doctors may suggest:

• Other medications that raise natural testosterone

• Adding medications that help the testes continue to produce sperm

• Freezing sperm before beginning therapy

This is an essential discussion for men of any age planning future parenthood.

Cardiovascular Considerations

The relationship between testosterone therapy and heart health is still being actively studied. Some research suggests that proper testosterone treatment in men with low testosterone may improve certain health markers such as:

• Blood sugar control

• Body fat distribution

• Muscle strength and activity levels

However, other studies have suggested that testosterone therapy might increase the risk of certain cardiovascular problems in some men, especially those who are older or who have pre-existing heart disease.

Because research has not produced a single clear answer, doctors approach this risk with caution. A healthcare provider will consider:

• Personal and family heart history

• Blood pressure and cholesterol levels

• Lifestyle factors (diet, exercise, smoking)

If a man has known heart disease, therapy may still be possible but requires closer follow-up.

Importance of Medical Supervision and Monitoring

Testosterone therapy should always be monitored by a licensed healthcare provider. Proper monitoring includes:

• Blood tests to check testosterone levels

• Red blood cell and hemoglobin checks

• PSA tests for prostate monitoring

• Review of symptoms and side effects

Monitoring helps ensure treatment remains safe and effective. Self-prescribing or using testosterone without supervision increases the risk of serious complications.

Testosterone therapy has clear benefits for men with clinically low testosterone, but it also has potential risks. Most side effects can be managed with careful dosing and regular monitoring. Understanding these risks allows men and their healthcare providers to work together to create a safe, effective treatment plan tailored to individual needs.

How Does Testosterone Therapy Affect the Prostate?

Understanding how testosterone therapy influences the prostate is important for men who are considering treatment. The prostate is a small gland located below the bladder. Its main job is to produce part of the fluid that makes up semen. The prostate depends on male hormones, especially testosterone and its derivative dihydrotestosterone (DHT), to grow and function.

Testosterone and Prostate Growth

Testosterone plays a natural role in prostate development. During puberty, rising testosterone levels cause the prostate to increase in size. Once adulthood is reached, the amount of testosterone in the body helps keep the prostate working normally. Because of this relationship, people once believed that raising testosterone levels through therapy would always lead to prostate growth, and possibly prostate cancer. However, research over the past 20 years has shown a more complex picture.

The prostate responds to hormones only up to a certain point. Many researchers describe this using the “saturation model.” In simple terms, this means the prostate needs only a certain amount of testosterone to function. Once that level is reached, extra testosterone does not necessarily cause more prostate growth. For most adult men, the prostate is already “saturated” with the amount of testosterone naturally present in the body. When testosterone levels are raised from low to normal levels during therapy, the prostate may not react in the way earlier theories suggested.

Testosterone Therapy and Prostate Size

Testosterone therapy can lead to a small increase in prostate size, but this increase is usually mild and often clinically insignificant. This means that although the prostate may become slightly larger, it does not always cause symptoms or health problems. In many cases, men receiving testosterone therapy do not notice changes in urination or prostate comfort.

However, every person responds differently. Men who already have an enlarged prostate, a condition known as benign prostatic hyperplasia (BPH), may experience more noticeable symptoms. These symptoms can include:

• Frequent urination

• Weak urine stream

• Difficulty starting urination

• Waking at night to urinate

If these symptoms are already present, testosterone therapy may need to be managed carefully. Healthcare providers may treat existing urinary symptoms before starting therapy or adjust the dose.

Dihydrotestosterone (DHT) and the Prostate

Testosterone in the body can convert to another hormone called dihydrotestosterone (DHT). DHT has stronger effects on prostate tissue than testosterone itself. Some studies show that testosterone therapy can increase levels of DHT, depending on the method used. For example, topical gels and creams may raise DHT levels more than injections. If DHT levels increase significantly, the prostate may respond by growing slightly.

Doctors may monitor DHT levels during therapy, especially if a man reports urinary symptoms or has a history of prostate enlargement. In some cases, medications that block DHT may be used, but only when medically necessary.

Clarifying Common Misconceptions

There are two major misunderstandings about testosterone therapy and the prostate:

Misconception 1: Testosterone therapy causes prostate cancer.

Current research does not show that restoring testosterone to normal levels causes prostate cancer. Studies have followed men on therapy for years and have not found higher prostate cancer rates compared to men not receiving therapy. However, more long-term data are still needed.

Misconception 2: Higher testosterone always enlarges the prostate.

Most adult prostates are already responding to a full hormonal signal. Raising testosterone from low to normal levels does not always lead to further growth.

Why Monitoring Still Matters

Even though most research does not show a strong link between testosterone therapy and prostate cancer, careful monitoring remains essential. Prostate cancer can exist without symptoms, and testosterone may stimulate growth of an existing cancer if it is already present. For this reason, men usually have a prostate-specific antigen (PSA) test and sometimes a digital rectal exam before starting therapy. These tests continue at regular intervals to ensure safety and detect changes early.

Testosterone therapy can influence the prostate, but the effects are generally modest when therapy is used to restore normal testosterone levels. Small changes in prostate size are possible, especially in men with existing prostate enlargement. The key to safe treatment is proper screening and ongoing monitoring. Understanding how testosterone interacts with the prostate helps men make informed decisions with their healthcare providers.

Does Testosterone Therapy Increase the Risk of Prostate Cancer?

For many years, doctors and patients believed that testosterone therapy could raise the risk of prostate cancer. This concern came from early research in the 1940s, when scientists discovered that men with advanced prostate cancer often improved when their testosterone levels were lowered. Because of this, the idea formed that more testosterone might “feed” prostate cancer, while less testosterone might slow it. This idea continued for decades, even though new research has provided a more detailed and updated understanding. Today, researchers and medical guidelines suggest that the relationship between testosterone and prostate cancer is more complex than previously believed.

Understanding the Historical Concern

The original concern was based on small studies in men who already had metastatic (advanced) prostate cancer. In those cases, lowering testosterone helped reduce symptoms. However, what was not understood at that time was whether normal or slightly increased testosterone levels could cause cancer to begin in the first place. For many years, there simply was not enough research to answer that question clearly. As a result, doctors took a cautious approach and often avoided prescribing testosterone to any man with a history of prostate cancer or even those considered at higher risk.

The Saturation Model

Advances in prostate biology led to a new theory called the saturation model. This model suggests that prostate cells only need a certain amount of testosterone to function. Once this level is reached, increasing testosterone levels above that point does not cause the prostate or prostate cancer cells to grow faster. In simpler terms, the prostate is “saturated” at a normal testosterone level.

This means:

• Very low testosterone levels may cause prostate tissues to shrink.

• Raising testosterone from very low levels to normal levels may cause some growth back to normal size.

• Raising testosterone above normal levels does not continue to stimulate growth in a significant way.

This theory helps explain why testosterone therapy in men with low testosterone does not consistently show an increased risk of prostate cancer in research studies.

What Current Research Shows

Many modern studies have examined men receiving testosterone therapy and tracked their prostate cancer outcomes. The large majority of these studies have found:

• Men using testosterone therapy do not have a higher rate of prostate cancer than men who do not use it.

• PSA levels (a blood test used to check prostate activity) may rise slightly at the start of therapy, but this is usually small and stabilizes over time.

• Men with carefully monitored testosterone therapy show no significant increase in aggressive prostate cancer cases.

Some studies even suggest that men with very low testosterone levels may have a higher risk of developing more aggressive prostate cancer, possibly because low testosterone might mask early warning signs. However, this area is still being studied and is not fully understood.

Men With a History of Prostate Cancer

For many years, testosterone therapy was considered unsafe for men who had been treated for prostate cancer. But newer research has shown that in men who have:

• Been successfully treated for prostate cancer, and

• Show no signs of recurrence, and

• Have been cancer-free for several years,

Testosterone therapy may be safely considered on a case-by-case basis under the care of a urologist or oncologist. Studies in these patients generally show no higher rate of recurrence when therapy is closely monitored.

However, testosterone therapy is not recommended for men with:

• Active prostate cancer

• Recurrent prostate cancer

• Metastatic prostate cancer

unless it is being used under very specialized medical care.

What Medical Guidelines Say

Professional medical organizations recognize that the older view linking testosterone therapy and prostate cancer risk was based on limited data. Today, many guidelines state:

• Testosterone therapy does not appear to increase the risk of prostate cancer in men without existing cancer.

• Prostate screening is still important.

• Men should be monitored regularly with PSA tests and prostate exams while on therapy.

Current research suggests that testosterone therapy does not cause prostate cancer, and for most men, it does not increase the risk of developing it. The relationship between testosterone and prostate cancer is not as simple as once believed. The prostate needs only a certain amount of testosterone to function, and raising levels above normal does not seem to “fuel” cancer growth.

However, careful screening and regular monitoring are essential. Every patient’s medical history, prostate health, and risk factors should be considered before and during therapy. Men should discuss the benefits and risks with their healthcare provider to make an informed choice.

Testosterone Therapy and Benign Prostatic Hyperplasia (BPH)

Benign Prostatic Hyperplasia (BPH) is a common condition in aging men. It refers to the enlargement of the prostate gland, which sits just below the bladder. As the prostate grows, it can press against the urethra, which is the tube that carries urine out of the body. This pressure can cause problems with urination. Many men who consider testosterone therapy are also dealing with BPH, so understanding the relationship between the two is important.

What Is BPH?

BPH is not prostate cancer. It is a non-cancerous growth of the prostate. The prostate naturally grows larger with age due to hormonal changes. For some men, this growth does not cause any symptoms. For others, it can lead to noticeable urinary issues.

Common symptoms of BPH include:

• Needing to urinate more often, especially at night

• Feeling urgent need to urinate

• Weak or slow urine stream

• Difficulty starting urination

• Feeling the bladder is not fully empty after urinating

• Dribbling at the end of urination

These symptoms are known as Lower Urinary Tract Symptoms (LUTS). They can range from very mild to very disruptive.

Why the Prostate Is Linked to Testosterone

The prostate is sensitive to androgens, which are male hormones like testosterone. In the body, some testosterone is converted into a more active hormone called dihydrotestosterone (DHT). DHT plays a key role in prostate development and size. This is why people used to believe that taking testosterone therapy would always make the prostate grow larger.

However, research has shown that the relationship is more complex. The prostate appears to reach a point of androgen saturation, meaning once hormone levels are “high enough,” adding more testosterone does not always lead to further growth.

Does Testosterone Therapy Worsen BPH Symptoms?

This is one of the most common concerns among men thinking about testosterone therapy.

Based on current research:

• For most men, testosterone therapy does not significantly worsen urinary symptoms.

• Some studies even report that urinary symptoms may improve after testosterone therapy, especially in men who had low testosterone to begin with.

Why might symptoms improve?

When testosterone levels are too low, the muscles and nerves involved in bladder function may become weaker. Restoring testosterone to a healthy level may support better urinary control, muscle tone in the pelvic region, and overall bladder function.

However, not all men will experience improvement. Some may notice no change, and a small number may have a temporary increase in urinary symptoms, especially in the early weeks of therapy.

What About Men with Moderate to Severe BPH?

Men with mild symptoms often tolerate testosterone therapy without issues.
Men with significant BPH symptoms may need closer monitoring.

Testosterone therapy does not cause BPH, but if the prostate is already enlarged, any additional stimulation may produce noticeable changes in urinary function.

Doctors may:

• Adjust the testosterone dose

• Recommend medications such as alpha blockers (which relax prostate muscles)

• Suggest 5-alpha reductase inhibitors (which reduce DHT and prostate size)

• Work together with a urologist to track symptoms more closely

This combined approach can help maintain urinary comfort and prostate safety.

Key Points to Remember

• BPH is common and happens naturally as men age.

• Testosterone therapy does not generally cause BPH or make it worse for most men.

• Some men may actually see an improvement in urinary symptoms with treatment.

• Men with moderate or severe urinary issues should be monitored carefully while on testosterone.

• Regular follow-up, PSA testing, and communication with a healthcare provider are important.

When to Contact a Doctor

Men should report symptoms such as:

• Sudden inability to urinate

• Burning or pain while urinating

• Blood in the urine

• Noticeable worsening of urinary symptoms

These may require evaluation to rule out infection or other prostate conditions.

Monitoring Prostate Health During Testosterone Therapy

Monitoring prostate health is an essential part of safe testosterone therapy. Testosterone can affect prostate tissue, so men who begin therapy should be checked regularly to make sure there are no signs of prostate problems, changes in urinary symptoms, or increases in prostate-specific antigen (PSA) levels. These checks allow healthcare providers to identify issues early and adjust treatment if needed. This section explains how monitoring works and why it is important.

Baseline Evaluation Before Starting Therapy

Before starting testosterone therapy, a complete health evaluation is recommended. The goal is to understand the man’s overall health, confirm true low testosterone, and check the prostate before any treatment begins. This helps doctors see if there are any risks or warning signs that need to be addressed.

A baseline evaluation usually includes:

• Blood Tests: To measure total testosterone, complete blood count, and PSA level.

• Digital Rectal Exam (DRE): A doctor gently checks the size and shape of the prostate with a gloved finger.

• Medical History Review: This includes asking about urinary symptoms, family history of prostate cancer, and any previous prostate issues.

These results help set a reference point. If the prostate already shows problems, the doctor may refer the patient to a urologist before starting therapy.

Regular PSA Monitoring During Testosterone Therapy

PSA stands for prostate-specific antigen. It is a protein made by prostate cells. A small amount in the blood is normal. Higher or changing levels may suggest prostate enlargement, inflammation, or in some cases, prostate cancer.

Once testosterone therapy begins, PSA levels should be checked regularly. A common monitoring schedule is:

• At 3 months after starting treatment

• At 6–12 months after starting treatment

• Every 6–12 months after that

If PSA levels remain stable, this usually means the prostate is responding normally. However, if PSA levels rise more quickly than expected, doctors may pause treatment to investigate. A rise does not always mean cancer, but it does require evaluation.

Understanding PSA Changes

Not all PSA changes are dangerous. Small, gradual increases can happen with age or with benign prostate enlargement. The concern is when PSA rises rapidly in a short period of time.

Doctors may watch for:

• A PSA increase of more than 1.4 ng/mL within 12 months

• A total PSA level higher than what is typical for the patient’s age

• Any abnormal results on a prostate exam

If any of these occur, the healthcare provider may refer the patient to a urologist for further tests such as prostate imaging or, in some cases, a biopsy.

Monitoring for Lower Urinary Tract Symptoms

Changes in urinary habits can also signal prostate issues. Men should report symptoms such as:

• Needing to urinate more often

• Trouble starting urination

• Weak urine stream

• Feeling unable to completely empty the bladder

• Getting up multiple times at night to urinate

These symptoms may suggest benign prostatic hyperplasia (BPH), which is common with aging. Testosterone therapy does not typically cause BPH to worsen, but symptoms should still be monitored.

When Treatment Should Be Paused or Reassessed

Testosterone therapy may be paused if:

• PSA increases too quickly

• A digital rectal exam shows prostate abnormalities

• Hematocrit (red blood cell level) becomes too high

• The patient develops moderate to severe urinary symptoms

Pausing therapy does not mean the patient cannot restart it. It simply allows time to find the cause of the change and ensure the patient’s safety.

Collaboration Between Healthcare Providers

Monitoring prostate health during testosterone therapy often involves more than one healthcare professional:

• Primary Care Physician: Oversees general health and basic monitoring.

• Urologist: Specializes in prostate conditions and provides evaluations when needed.

• Endocrinologist: Helps manage hormone levels and therapy decisions.

Working together ensures the patient receives safe, balanced care.

Monitoring prostate health during testosterone therapy is essential. Regular testing and communication allow men to benefit from testosterone treatment while keeping prostate health protected. Consistent follow-up helps detect problems early, supports safe treatment decisions, and provides confidence for both patient and provider.

Who Should Not Use Testosterone Therapy?

Testosterone therapy can be helpful for many men with medically confirmed low testosterone levels. However, it is not safe or appropriate for everyone. Some medical conditions, personal health risks, and life situations can make testosterone therapy risky. This section explains who should avoid testosterone therapy and why careful medical evaluation is important before starting treatment.

Men With Active or Suspected Prostate Cancer

Men who currently have prostate cancer, or who are being evaluated for possible prostate cancer, should not start testosterone therapy. This is because testosterone can act as a growth signal for prostate cells. While research shows that normal testosterone levels do not necessarily cause prostate cancer, doctors are cautious. If cancer is present, adding testosterone could possibly help the cancer grow faster.

Signs that require further evaluation before therapy include:

• Elevated PSA (Prostate-Specific Antigen)

• Abnormal digital rectal exam

• History of prostate cancer with incomplete treatment follow-up

Healthcare providers will usually refer these men to a urologist before considering any hormone treatment. If prostate cancer has been treated in the past, and the patient is now cancer-free, testosterone therapy may still be possible, but only under specialist supervision and close monitoring.

Men With Severe, Untreated Prostate Enlargement or Urinary Symptoms

Some men have a condition called Benign Prostatic Hyperplasia (BPH), which means the prostate gland is enlarged. BPH can cause symptoms such as:

• Weak urine flow

• Needing to urinate often, especially at night

• Sudden strong urges to urinate

• Difficulty starting urination

Testosterone therapy does not always make BPH worse, but if symptoms are already severe, therapy could increase discomfort. For this reason, men with severe or untreated BPH are not good candidates until the urinary symptoms are under control. A urologist may recommend medication or other treatments first.

Men Who Are Planning to Conceive

Testosterone therapy can reduce sperm production because it signals the body to slow or stop natural testosterone production in the testicles. This reduces sperm-making hormone signals from the brain. Over time, sperm count may go down, and fertility may be affected.

For men who want to father children in the near future:

• Testosterone therapy should be avoided

• Other medical treatments may be used instead to raise testosterone while preserving fertility (for example, medications like clomiphene citrate or hCG)

This is an important discussion for younger men or couples planning a family.

Men With Uncontrolled Sleep Apnea

Sleep apnea is a condition where breathing stops or becomes very shallow during sleep. It can cause:

• Loud snoring

• Daytime fatigue

• Memory or concentration problems

• Increased risk of heart disease

Testosterone therapy may make sleep apnea worse in some men. If sleep apnea has not been diagnosed or treated, testosterone therapy can increase health risks. Men with known sleep apnea can often still use testosterone therapy if the sleep apnea is properly treated first (for example, with a CPAP machine).

Men With Elevated Hematocrit Levels

Hematocrit refers to the number of red blood cells in the blood. Testosterone therapy can cause the body to make more red blood cells. If hematocrit levels get too high, the blood becomes thicker, and the risk of blood clots, stroke, or heart problems increases.

Men who already have:

• High hematocrit

• History of blood clots

• Polycythemia (a condition of too many red blood cells)

may be told to avoid testosterone therapy or require extra monitoring. Blood tests are required before and during therapy to watch hematocrit levels.

Why Individual Medical Evaluation Matters

Every person’s health situation is unique. A treatment that is safe for one man may not be safe for another. Before prescribing testosterone, a doctor will:

1. Review medical history

2. Perform physical exams

3. Order blood tests

4. Evaluate prostate health

5. Discuss fertility goals

In many cases, risks can be reduced through careful planning and monitoring. However, for some men, avoiding testosterone therapy is the safest choice.

Testosterone therapy can provide benefits, but it is not appropriate for everyone. Men with prostate cancer, severe BPH, plans for future fertility, uncontrolled sleep apnea, or high hematocrit levels should be cautious or avoid therapy. Working closely with a healthcare provider ensures safe, informed decisions based on a person’s specific health needs.

Conclusion

Testosterone therapy is used to help men whose bodies no longer make enough testosterone on their own. Low testosterone can affect daily life by reducing energy, lowering sexual desire, causing mood changes, and weakening muscle and bone strength. For many men, testosterone therapy can provide meaningful improvements in these symptoms and can help restore a sense of well-being. However, testosterone therapy is not a simple or automatic treatment. It is a medical therapy that must be evaluated, prescribed, and monitored with care.

One of the most important concerns for men and healthcare providers is how testosterone therapy may affect the prostate. The prostate is a gland that naturally reacts to hormones, including testosterone. Because prostate cancer and benign prostate enlargement are common in aging men, there has long been fear that adding testosterone could cause harm. Earlier medical beliefs were based on the idea that higher testosterone levels always stimulated prostate growth. This led to decades of caution and hesitation around testosterone therapy. Over time, research has improved our understanding of how testosterone and the prostate interact.

Current scientific evidence does not show that testosterone therapy increases the risk of developing prostate cancer in men who do not already have the disease. The relationship is more complex than once believed. The “saturation model” suggests that prostate cells require only a certain amount of testosterone to function, and once this level is reached, additional testosterone does not keep increasing prostate growth. This means that raising testosterone from low levels to normal levels does not appear to fuel new prostate cancer. Even so, the medical community agrees that more long-term research is still needed to fully understand the risks over many years.

Prostate health remains important because men taking testosterone therapy may already be at the age when prostate problems are more likely to occur. Benign prostatic hyperplasia (BPH), which leads to urinary symptoms like weak flow or frequent nighttime urination, is very common in older men. Some may wonder whether testosterone therapy will worsen these symptoms. Research findings are mixed but generally show that testosterone therapy does not significantly worsen urinary symptoms for most men. In some cases, symptoms stay the same, and in others, they may even improve, especially if low testosterone was weakening muscle strength around the bladder and pelvic area. However, men who already have severe urinary symptoms should be evaluated carefully before starting therapy.

Because of these factors, monitoring is a key part of safe testosterone treatment. Before starting therapy, men should have a prostate exam and a blood test called PSA, which measures prostate-specific antigen. PSA levels are used to track prostate health over time. During treatment, regular follow-up visits and repeat PSA tests are needed to watch for meaningful changes. If PSA levels rise faster than expected, if urinary symptoms suddenly worsen, or if a prostate exam shows a concern, the healthcare provider may pause therapy and investigate further. This careful oversight helps reduce risk and ensures that any changes are recognized early.

Men considering testosterone therapy should also understand that it is not suitable for everyone. Men with active prostate cancer should not use testosterone therapy. Men with very high PSA levels or severe untreated urinary symptoms need evaluation before starting. Those who plan to have children should be aware that testosterone therapy can lower sperm production. It is important that treatment decisions are made based on individual health, medical history, and personal goals.

In summary, testosterone therapy can offer real benefits when used correctly and monitored carefully. It can help restore physical strength, improve mood, and increase sexual well-being for men with clinically diagnosed low testosterone. At the same time, attention to prostate health is essential. The current body of research suggests that testosterone therapy does not raise the risk of prostate cancer when used to restore normal hormone levels; however, regular monitoring and individualized medical evaluation are necessary to ensure safety.

Men who are thinking about testosterone therapy should discuss their symptoms, hormone test results, prostate health, and overall medical history with a healthcare professional. Shared decision-making, where the patient and provider talk openly about goals, expectations, and possible risks, leads to the best outcomes. This balanced, informed approach allows men to receive the potential benefits of testosterone therapy while protecting long-term health.