Testosterone And Prostate Cancer: What Men Should Know

Written by the UPGUYS Editorial Team

Published on April 15, 2025

For decades, testosterone has been viewed with caution when it comes to prostate cancer. Many men have heard that increasing testosterone levels might "fuel" the growth of prostate cancer, leading to fear or hesitation around treatments like testosterone replacement therapy (TRT). 

Testosterone Replacement Therapy

UPGUYS: Online, Easy & Discreet

Start TRT Program Now

This concern has impacted men in Canada and elsewhere, where access to TRT has grown, but so have questions about its long-term safety, particularly for those over 40. 

However, the conversation is changing. In recent years, researchers and clinicians have re-examined the relationship between testosterone and prostate cancer, uncovering findings that challenge outdated assumptions. 

Rather than causing prostate cancer, new evidence suggests testosterone may play a far more nuanced role, one that's safer and more manageable than previously believed. 

This article is for men who are exploring TRT in Canada, those concerned about prostate health, and anyone wanting science-based clarity on the risks, myths, and medical realities of testosterone therapy. Whether you're considering treatment or just want to understand your options, this guide will help you separate fact from fear. 

Topics covered in this article: 

Where the Concern About Testosterone Began 

The fear that testosterone causes or accelerates prostate cancer can be traced back to a single, influential study from the 1940s. In this early research, doctors Charles Huggins and Clarence Hodges observed that reducing testosterone levels in men with advanced prostate cancer appeared to slow the disease. Their findings led to the belief that testosterone "feeds" prostate cancer and that raising testosterone could make it grow faster. 

Testosterone Replacement Therapy

UPGUYS: Online, Easy & Discreet

Start TRT Program Now

This idea took hold quickly and influenced medical thinking for decades. For a long time, men with prostate cancer—or even those at risk—were advised to avoid any treatments that might increase testosterone levels, including testosterone replacement therapy (TRT). Physicians were taught that testosterone was dangerous for the prostate, and many men were steered away from hormone therapy, even if they were suffering from clear symptoms of low testosterone. 

Despite the limited size and scope of the original study, its conclusions stuck in the public and medical imagination. This caution persisted in part because there weren't many large-scale studies challenging it and because the risks associated with prostate cancer made doctors understandably conservative. 

However, as research methods improved and our understanding of hormone biology deepened, newer studies began to challenge these long-standing beliefs, leading to a much more nuanced and evidence-based view of the relationship between testosterone and prostate cancer. 

What New Research Reveals About Testosterone and Cancer 

In the last two decades, a growing body of modern research has disputed the long-held belief that testosterone causes or worsens prostate cancer. Large-scale studies and clinical reviews have shown that, for most men, testosterone replacement therapy (TRT) does not increase the risk of developing prostate cancer, nor does it appear to accelerate the disease in men without an existing diagnosis. 

Multiple well-designed studies have found that men undergoing TRT are no more likely to develop prostate cancer than men with low or normal testosterone levels. In fact, some data suggest that men with low testosterone may be more likely to develop aggressive forms of prostate cancer, challenging the notion that lower hormone levels are protective. 

Testosterone Replacement Therapy

UPGUYS: Online, Easy & Discreet

Start TRT Program Now

A key concept that has emerged from this research is the "saturation model." This theory proposes that prostate cancer cells respond to testosterone only up to a certain point—once a man's testosterone reaches a basic, functional threshold, additional testosterone does not stimulate more growth. In other words, the prostate becomes "saturated" with testosterone, and adding more doesn't fuel the fire. 

This model helps explain why TRT appears safe for most men, as it restores testosterone to normal physiological levels, not supraphysiological levels like anabolic steroid abuse might. The saturation model has become widely accepted in the field of urology and offers a clearer, more reassuring framework for evaluating TRT in Canada and beyond. 

Can Low Testosterone Increase Prostate Cancer Risk? 

While many men assume that lower testosterone levels offer protection against prostate cancer, newer research suggests the opposite may sometimes be true. Several studies have found a surprising connection between low testosterone and more aggressive forms of prostate cancer. In fact, men diagnosed with prostate cancer who also have low T levels may be at higher risk for advanced or high-grade tumours. 

This challenges the long-standing assumption that less testosterone is always safer. In reality, low testosterone doesn't offer immunity from prostate cancer, and in some cases, it may signal a more complex hormonal imbalance. 

Here's what the latest evidence highlights: 

1. Men with low T may have a higher likelihood of aggressive or advanced prostate cancer 
2. Lower testosterone is not protective and can be misleading when evaluating prostate risk 
3. Hormonal balance, rather than suppression, is emerging as the key to prostate health 

Low testosterone can also influence immune response, cellular repair, and how the body manages abnormal cell growth. That's why restoring testosterone to a healthy, functional range with TRT in Canada, when medically appropriate, does not increase prostate cancer risk—and may support broader health outcomes. 

Testosterone Replacement Therapy

UPGUYS: Online, Easy & Discreet

Start TRT Program Now

Is TRT Safe If You Have or Had Prostate Cancer? 

For years, men with a history of prostate cancer were told that testosterone therapy was completely off-limits. But thanks to evolving research and more nuanced clinical guidelines, that narrative is shifting, especially for men who have been successfully treated and are now experiencing the symptoms of low testosterone. 

While caution is still necessary, testosterone replacement therapy (TRT) is no longer considered an automatic "no" for men with a prostate cancer history. Instead, doctors are now evaluating safety on a case-by-case basis, guided by recent studies and updated professional recommendations. 

Here's what we know: 

1. TRT may be considered for men with a history of localized, treated prostate cancer, particularly those with no evidence of disease recurrence for at least 1–2 years. 
2. Major medical organizations, such as the American Urological Association (AUA) and the European Association of Urology (EAU), now support the carefully monitored use of TRT in select prostate cancer survivors. 
3. TRT is generally contraindicated in men with active or advanced prostate cancer, or in cases where cancer has not been fully treated or is being actively monitored (e.g., during active surveillance). 

In these situations, the benefits of TRT—improved energy, mood, muscle mass, and libido—must be weighed carefully against potential risks. That's why any man with a history of prostate cancer should work closely with a urologist or men's health specialist to determine if TRT is safe and appropriate. 

How PSA Testing and Monitoring Fit Into TRT 

When considering testosterone replacement therapy (TRT)—especially for men over 40 or those with prostate concerns—prostate monitoring is essential. The key tool for this is the PSA test (prostate-specific antigen), a simple blood test that helps detect changes in the prostate that may indicate inflammation, enlargement, or cancer. 

Here's how PSA monitoring fits into safe TRT use: 

1. Baseline PSA testing is usually required before starting TRT to assess prostate health. This gives doctors a reference point for future comparisons. 
2. Once on TRT, regular PSA tests are typically done every 3 to 6 months in the first year, and then annually, to detect any unusual increases. 
3. A significant rise in PSA levels or the presence of other symptoms—such as urinary issues or changes detected on digital rectal exams—may prompt further evaluation by a urologist. 

Monitoring isn't just about risk prevention. It's about giving men peace of mind. When done properly, PSA testing makes it possible to enjoy the benefits of TRT in Canada while keeping a close watch on prostate health. 

Ultimately, a strong partnership with your doctor ensures that TRT is both effective and safe, especially when combined with routine prostate assessments tailored to your age and health history. 

What to Ask Your Doctor Before Starting TRT 

If you're considering testosterone replacement therapy, especially with concerns about prostate health, the most important step is having an open, informed conversation with your doctor. Don't hesitate to ask direct questions. This isn't just about hormone levels. It's about protecting your long-term well-being. 

Here are key questions to ask: 

1. Can we test my testosterone and PSA levels before starting treatment? 
2. What is my current risk for prostate cancer based on my age, family history, and health profile? 
3. How often will you monitor my PSA and testosterone levels during therapy? 
4. If I've had prostate cancer in the past, is TRT still an option for me? 
5. Are there alternative treatments if I'm not a good candidate for TRT? 

These conversations help you understand not just if TRT is right for you, but how it will be managed safely over time. Working with a provider who's familiar with TRT protocols and prostate monitoring—or who can refer you to a urologist—ensures you'll get personalized care that fits both your goals and your health history. 

When you're ready to move forward, knowledge is your best ally. 

Testosterone Replacement Therapy

UPGUYS: Online, Easy & Discreet

Start TRT Program Now



Conclusion: Testosterone, Prostate Cancer, and Informed Decisions 

For decades, the idea that testosterone causes prostate cancer kept many men from seeking treatment for low T. But today, we know better. Modern research shows that testosterone therapy does not increase prostate cancer risk when used appropriately, and in some cases, low testosterone may even be linked to more aggressive disease. 

That doesn't mean you should dive into treatment without careful consideration. Instead, it means you can make choices based on facts, not fear. With baseline PSA testing, regular monitoring, and support from a knowledgeable provider, TRT in Canada can be both safe and life-enhancing—even for men with a history of prostate issues. 

If you've been avoiding testosterone therapy because of outdated warnings, it may be time to revisit the conversation. Ask the right questions, get the right tests, and work with the right professionals. Your energy, focus, and quality of life are worth protecting—and now, more than ever, you can do that with confidence and clarity. 

Frequently Asked Questions (FAQs) 

Testosterone & Prostate Cancer