Most men who need to know about testosterone replacement therapy never look into it.
Dr. Jeff Kindred, DONot because they aren’t curious. Because they’ve already heard enough to be afraid.
Prostate cancer. Heart attacks. Steroids. The conversation gets shut down before it starts, often by a physician who brings up one of those concerns and moves on. And so men continue to feel the way they’ve been feeling — fatigued, mentally foggy, losing muscle despite trying, carrying more body fat than they used to — assuming it’s just aging. Just something to accept.
Some of it is aging. But not all of it.
Testosterone levels in men decline roughly 1–2% per year after age 30. [1] By the time a man is in his late 40s or 50s, that accumulation is clinically meaningful for many — and the fears standing between him and an evidence-based conversation about treatment deserve a real answer, not a dismissal.
What Testosterone Actually Does
Testosterone is often reduced in the cultural conversation to libido and sexual function. That framing is both reductive and clinically misleading.
Testosterone is a metabolic hormone. It influences muscle protein synthesis, fat distribution, bone density, red blood cell production, insulin sensitivity, mood, cognitive function, energy, and cardiovascular health. [2] When levels decline significantly, the downstream effects touch almost every system in the body.
Low testosterone is associated with increased fat mass and decreased lean mass, reduced bone density, depressed mood, cognitive decline, metabolic dysfunction, and — critically — increased cardiovascular risk and all-cause mortality. [3] Low testosterone is not a benign condition. It has consequences, and those consequences compound over time.
Which makes the fears around treatment worth examining carefully.
Myth 1: Testosterone Causes Prostate Cancer
This is the most persistent fear, and it has a specific origin. In 1941, a physician named Charles Huggins published research showing that castration — removing testosterone entirely — caused prostate cancer to regress. The implication that followed, and that persisted in medical education for decades, was that testosterone “feeds” prostate cancer.
The problem is that the evidence never actually supported that conclusion for men with normal testosterone levels.
A landmark review by urologist Abraham Morgentaler proposed what is now called the saturation model: the prostate has androgen receptors that become saturated at relatively low testosterone concentrations, somewhere around 200–250 ng/dL. Above that threshold, adding more testosterone does not meaningfully stimulate further prostate tissue growth. [4]
Multiple subsequent studies have failed to demonstrate that testosterone therapy increases the risk of prostate cancer in men without pre-existing disease. A large meta-analysis found no significant increase in prostate cancer incidence with TRT. [5] The American Urological Association and the Endocrine Society have both updated their guidance to reflect this — TRT is not contraindicated in most men with previously treated, low-risk prostate cancer after a period of stability.
The fear was built on an 80-year-old inference that the data has not consistently supported. That doesn’t mean monitoring isn’t important — PSA should be checked at baseline and followed during treatment. But PSA monitoring and categorical avoidance of testosterone are not the same recommendation.
Myth 2: Testosterone Causes Heart Attacks
This fear has a more recent origin. In 2010, a study published in the New England Journal of Medicine was stopped early after men on testosterone therapy had higher rates of cardiovascular events. [6] The study generated significant concern and influenced prescribing patterns for years.
What got less attention was how that study was designed. The participants were older men with significant pre-existing conditions — many had limited mobility, diabetes, and established cardiovascular disease. The study was small, stopped early, and not designed as a definitive cardiovascular safety trial. Its findings were real but narrow, and they were extrapolated far beyond what the data supported.
The definitive answer came in 2023.
The TRAVERSE trial was a large, randomized, placebo-controlled trial specifically designed to assess cardiovascular safety of testosterone therapy in men with low testosterone and pre-existing cardiovascular risk — exactly the high-risk population that had caused concern. The result: no significant increase in heart attacks, strokes, or cardiovascular death in the testosterone group compared to placebo. [7]
In fact, the picture of untreated low testosterone looks worse for the heart than the picture of treated low testosterone. Multiple studies have found that low testosterone is independently associated with increased cardiovascular mortality. [3] The risk calculation is more nuanced than the original fear suggested.
Important caveats remain. The TRAVERSE trial did find higher rates of atrial fibrillation (an irregular heart rhythm) and blood clots in the testosterone group — both worth discussing and monitoring individually. Red blood cell counts also tend to rise with testosterone therapy, which can increase clotting risk if left unchecked, and requires routine blood monitoring. These are manageable. They are not reasons to avoid the conversation.
Myth 3: It’s Just Steroids
This one is about dose and intent, and the difference matters enormously.
Anabolic steroid use in bodybuilding involves supraphysiologic doses — testosterone levels driven well above normal physiologic range, often stacked with other compounds, without medical supervision or monitoring. The health risks associated with that practice are real and well-documented.
Testosterone replacement therapy is something entirely different. The goal is to restore testosterone to a normal physiologic range for the patient — to bring levels from deficient back to where they should be, not to push them beyond normal. Doses, delivery methods, and monitoring are calibrated to achieve that specific outcome.
Conflating the two is like conflating therapeutic corticosteroids for an inflammatory condition with the long-term high-dose steroid use that causes serious side effects. The molecule is the same. The dose, context, and intention are completely different.
How to Actually Evaluate Testosterone
One reason men are told their testosterone is “fine” when it may not be: the standard lab reference range is very wide. Most lab normals span from approximately 300 to 1000 ng/dL. That range was derived from population averages that include men of all ages and health statuses, including those who are ill, sedentary, or elderly. A 45-year-old man with a total testosterone of 310 ng/dL is technically “normal” by that standard. He may also feel terrible.
A proper evaluation looks at more than a single total testosterone number. Free testosterone — the biologically active fraction not bound to proteins — matters significantly and can be low even when total testosterone appears adequate. Sex hormone-binding globulin (SHBG) affects how much testosterone is actually available to tissues. LH and FSH help distinguish the source of the problem. Symptoms are part of the clinical picture and cannot be separated from the lab values.
The question is not just whether a number falls within a population reference range. The question is whether that number, in context, explains how someone feels — and whether optimizing it would change their trajectory.
A Note on Getting This Right
Testosterone therapy has become significantly more accessible in recent years, and that accessibility has real value. Men who previously couldn’t get a physician to take their symptoms seriously now have options.
But accessibility without oversight is its own problem.
A growing number of men are managing testosterone through online platforms that operate largely on protocol — a single lab value, a standard dose, a renewal every few months. No one knows their cardiovascular history. No one is tracking how their blood counts are trending over time. No one is adjusting the approach based on how they actually feel rather than where a number lands on a reference range. And when something isn’t working, there isn’t a physician who knows them well enough to understand why.
Testosterone optimization done well is not a set-and-forget prescription. It requires a physician who knows your full picture — your baseline labs, your symptoms, your history, your goals — and who can make small, informed adjustments over time as your body responds. The difference between a dose and delivery method that works and one that doesn’t is often subtle. Getting it right is a process, not a transaction.
That relationship is the part most online platforms can’t offer. And it’s the part that matters most. We’ve written about why the physician-patient relationship is the most underrated tool in medicine — and testosterone management is one of the clearest examples of why.
The Bottom Line
The fears around testosterone therapy are not entirely unfounded — they came from somewhere, and monitoring during treatment is genuinely important. But the evidence does not support the reflexive avoidance that has kept many men from having a real conversation about their hormones.
Prostate cancer risk with TRT is not supported by the current evidence base in men without pre-existing disease. Cardiovascular risk in the general population of men with low testosterone has not been demonstrated in large, well-designed trials — and the TRAVERSE trial specifically addressed the highest-risk population and found no increase in major cardiac events. Physiologic testosterone replacement is not the same as anabolic steroid use.
What is well-supported: low testosterone has real consequences for body composition, bone health, metabolic function, mood, cognition, and cardiovascular risk. Leaving it untreated because of fears that don’t hold up to scrutiny is its own clinical decision — and not necessarily the safer one.
At Hi, Finch Health, testosterone evaluation is part of how we think about the full clinical picture for every male patient. If you’ve been told your levels are normal and you don’t feel like yourself, that conversation is worth having. Set up a consultation with Dr. Kindred to get started.
If you found this useful, you may also want to read about why DEXA scans are one of the most important tests most people aren’t getting, or our post on perimenopause and why it’s so frequently missed. We’ve also written about GLP-1 medications and what the research actually shows about muscle loss.
References
- Harman SM, et al. “Longitudinal effects of aging on serum total and free testosterone levels in healthy men. Baltimore Longitudinal Study of Aging.” J Clin Endocrinol Metab. 2001;86(2):724–731. PubMed
- Bhasin S, et al. “Testosterone therapy in men with hypogonadism: an Endocrine Society clinical practice guideline.” J Clin Endocrinol Metab. 2010;95(6):2536–2559. PubMed
- Laughlin GA, et al. “Low serum testosterone and mortality in older men.” J Clin Endocrinol Metab. 2008;93(1):68–75. PubMed
- Morgentaler A, Traish AM. “Shifting the paradigm of testosterone and prostate cancer: the saturation model and the limits of androgen-dependent growth.” Eur Urol.2009;55(2):310–320. PubMed
- Cui Y, et al. “The effect of testosterone replacement therapy on prostate cancer: a systematic review and meta-analysis.” Prostate Cancer Prostatic Dis. 2014;17(2):132–143. PubMed
- Basaria S, et al. “Adverse events associated with testosterone administration.” NEJM. 2010;363(2):109–122. PubMed
- Lincoff AM, et al. “Cardiovascular Safety of Testosterone-Replacement Therapy.” NEJM. 2023;389(2):107–117. PubMed