For a long time, this was the question that ended the conversation. A man would raise the idea of testosterone therapy with his clinician, someone would mention the prostate, and the discussion stopped there.
That reflex came from somewhere real. For most of the twentieth century, the working assumption was that testosterone fed prostate cancer, so giving a man more of it was considered dangerous by definition. That belief shaped how clinicians were trained and how men were counselled for decades.
The evidence has moved. It has not moved as far as some online marketing suggests, and it has moved further than the old blanket warning implied. Here is what the guidelines and the trial data actually say, and what is still genuinely unsettled.
Does testosterone therapy cause prostate cancer?
Current guideline bodies say there is no evidence that testosterone therapy causes prostate cancer.
The Canadian Urological Association addressed this directly in its 2021 testosterone deficiency guideline. Despite the historical teaching about testosterone and prostate cancer biology, the CUA describes consistent evidence that testosterone therapy does not increase prostate cancer risk. The guideline points to pooled randomized data and to the observation that men with the highest naturally occurring testosterone levels do not show higher PSA levels or a greater subsequent risk of prostate cancer than men with the lowest levels.
The American Urological Association reached a similar position in its 2018 guideline, advising clinicians to inform patients of the absence of evidence linking testosterone therapy to the development of prostate cancer.
Two things are worth naming about that phrasing. “Absence of evidence linking” is a careful statement. It is not the same as “proven safe over a lifetime.” Guideline panels choose that wording deliberately.
What did the TRAVERSE trial find about the prostate?
The TRAVERSE trial reported low rates of prostate cancer and other prostate events in both the testosterone and placebo groups, and the investigators cautioned against reading that as proof of equal risk.
TRAVERSE, published in the New England Journal of Medicine in 2023, was designed primarily to answer the cardiovascular safety question in men with hypogonadism who had existing cardiovascular disease or were at high risk for it. A companion analysis of prostate outcomes was published in JAMA Network Open in December 2023.
The prostate analysis found low incidences of high-grade prostate cancer, any prostate cancer, acute urinary retention, and invasive procedures for benign prostatic hyperplasia in men receiving testosterone compared with placebo. Prostate cancer diagnoses were in the low double digits in each group across more than 5,000 participants.
The authors then added a caution that rarely survives the trip into a social media post. Because the number of prostate cancer events was small, they wrote, the findings should not be interpreted to imply that the risk of prostate cancer in the testosterone and placebo groups was similar. A small number of events in each arm limits what statistics can tell you.
There is a second limitation worth understanding. Men entering TRAVERSE were screened to exclude those at higher prostate cancer risk, and entry generally required a PSA at or below 3.0 ng/mL. So the trial tells us about carefully selected men who were followed for a median of roughly three years. It does not tell us about men who were not screened that way, and it does not tell us what happens over fifteen years.
If you have read our piece on what TRAVERSE found about cardiovascular safety, the same principle applies here. A trial answers the question it was built to answer, in the population it enrolled, over the time it ran.
Is the long-term prostate question settled?
No, and the Endocrine Society said so plainly in July 2026.
In a public statement on testosterone replacement therapy, the Endocrine Society noted that while recent studies have addressed some concerns, long-term safety, including for prostate cancer, remains unestablished. The statement gives the reason: prostate cancer develops slowly, and trials may not have followed men long enough to detect a difference. Risk assessment before starting and careful monitoring during treatment therefore remain essential.
The same statement called for a long-term men’s health research programme, described as analogous to the Women’s Health Initiative, to close the remaining evidence gaps.
That is the honest position. Short and medium term data are reassuring. Multi-decade data do not exist yet. A clinician who tells you the prostate question is fully closed is going further than the evidence supports, and so is a clinician who tells you testosterone causes prostate cancer.
What prostate assessment happens before therapy is considered?
Guideline-based care includes a prostate risk assessment before any decision about therapy, not after.
In practice, that generally means a baseline PSA and a discussion of prostate cancer screening appropriate to the man’s age, family history, and other risk factors. The CUA directs clinicians to follow the existing Canadian evidence-based guidelines for prostate cancer screening and early diagnosis rather than treating testosterone therapy as a separate screening universe.
It also means an honest conversation about urinary symptoms, since lower urinary tract symptoms are common in the same age group and can complicate the picture in either direction.
None of this is unique to hormone care. It is the same principle that applies anywhere in medicine: you establish a baseline before you change a variable, because otherwise you cannot interpret what happens next.
What monitoring happens during therapy?
Monitoring during testosterone therapy includes ongoing prostate surveillance alongside blood work.
The CUA guideline states that PSA testing and digital rectal examination should be performed to monitor prostate health in accordance with evidence-based guidelines for prostate cancer screening. Monitoring generally involves blood work at defined intervals in the first year and then at longer intervals once a man is stable, with a review of symptoms at each point.
Prostate surveillance is one part of a broader monitoring picture. Blood counts, blood pressure, and symptom review are also part of standard follow-up. Testosterone products carry a labelled warning about increased blood pressure, which is one of the reasons blood pressure is checked rather than assumed.
The practical point is this. Monitoring is not an administrative formality attached to a prescription. It is the mechanism by which a decision stays a good decision over time, and it is the piece most likely to be missing in a model where a man never speaks to the same clinician twice.
Are there men for whom testosterone therapy is not appropriate?
Yes, and prostate history is part of that assessment.
The CUA guideline states that patients with metastatic or high-risk prostate cancer who are likely to require androgen deprivation therapy should not be offered testosterone therapy. That is a moderate level of evidence with a strong recommendation.
For men with a history of localized prostate cancer that has been treated with surgery or radiation, or who are on active surveillance without evidence of active disease, the CUA describes that a medically supervised trial of testosterone therapy can be considered, with close follow-up. The AUA takes a comparable position, advising that men with a history of prostate cancer be told there is inadequate evidence to quantify the risk and benefit balance in their situation.
Both of those are conversations, not rules that can be applied from a web form. They require the actual clinical history in front of you.
Why does the old warning still shape the conversation?
Because the original theory was built on a small amount of very influential evidence, and it took decades to test properly.
The link between androgens and prostate cancer growth was established in the 1940s in men with advanced, metastatic disease. What happened next was an extrapolation: if lowering testosterone helps advanced prostate cancer, raising it in a man without prostate cancer must be harmful. That was reasonable at the time. It was also not directly tested for a long time, and when it was tested, it did not hold up in the way the theory predicted.
This history matters for a practical reason. If your family doctor was trained twenty five years ago, the caution they express is not obstruction. It reflects what the evidence looked like then. The useful response is not to dismiss it but to bring current guidance into the conversation.
Frequently asked questions
Does testosterone therapy raise PSA?
Some men show a modest rise in PSA after starting testosterone therapy, which is one reason PSA is measured at baseline and monitored afterward. What a change means depends on the size of the change, the timing, and the individual clinical picture. It is interpreted by a clinician who has the baseline value, not read off a single number in isolation.
Can I have testosterone therapy if my father had prostate cancer?
A family history of prostate cancer is part of the risk assessment rather than an automatic exclusion. It affects how prostate cancer screening is approached and how monitoring is planned. This is a conversation to have with a clinician who has your full history.
Does testosterone therapy make an enlarged prostate worse?
The CUA guideline notes that in studies of hypogonadal men, testosterone therapy had no significant impact on prostate volume, and describes studies showing improvement in urinary symptoms and flow measures in some men. Urinary symptoms are still assessed before and during therapy, because they are common in this age group for reasons unrelated to hormones.
Should I get a PSA test before I even ask about testosterone?
You do not need to arrange testing before an assessment. A baseline prostate risk assessment is part of a structured intake, and the clinician will determine which tests are appropriate based on your age, history, and symptoms.
Is the prostate question the reason my doctor said no?
Sometimes, and sometimes not. Prostate concern is one common reason, but a clinician may also be weighing whether symptoms have another explanation, whether testing was done correctly, or whether therapy is appropriate at all. Asking directly which concern is driving the answer usually produces a more useful conversation than pressing for a prescription.
What happens if you want a structured assessment
Prosper Men’s Health starts with an Initial Health Intake. It is a scheduled virtual appointment focused on understanding your history rather than reaching a conclusion in the first fifteen minutes.
The intake covers your symptoms and how long they have been present, your medical and family history including prostate history, your medications, and the lifestyle and metabolic factors that influence hormone levels. If blood work is appropriate, you receive requisitions and have testing done at a lab near you, with timing that reflects how testosterone levels behave through the day.
Results are reviewed with you at a follow-up appointment. Some men leave that conversation with a plan that includes hormone therapy. Some leave with a different explanation for their symptoms and a plan that addresses it. Some leave with a recommendation to work with their family physician on something else entirely. All three are legitimate outcomes of a proper assessment.
You can review what the assessment involves on our services page or read through our frequently asked questions.
Educational disclaimer. This article is general health education. It is not medical advice, it is not a substitute for assessment by a qualified clinician, and reading it does not create a clinician-patient relationship. Decisions about testing, diagnosis, and treatment should be made with a clinician who knows your full medical history. If you have symptoms that concern you, speak with your primary care provider or book an assessment.
Sources
- Canadian Urological Association. Canadian Urological Association guideline on testosterone deficiency in men: Evidence-based Q&A. Canadian Urological Association Journal, 2021.
- American Urological Association. Evaluation and Management of Testosterone Deficiency: AUA Guideline, 2018.
- Endocrine Society. Testosterone Therapy in Men With Hypogonadism: An Endocrine Society Clinical Practice Guideline. Journal of Clinical Endocrinology and Metabolism, 2018.
- Endocrine Society. Statement on Testosterone Replacement Therapy, July 2026.
- Lincoff AM, et al. Cardiovascular Safety of Testosterone-Replacement Therapy (TRAVERSE). New England Journal of Medicine, 2023.
- Bhasin S, et al. Prostate Safety Events During Testosterone Replacement Therapy in Men With Hypogonadism: A Randomized Clinical Trial. JAMA Network Open, 2023.
- U.S. Food and Drug Administration. FDA issues class-wide labeling changes for testosterone products, 2025.