Testosterone has become one of the most misunderstood topics in modern medicine. For some people, it is still mentally filed under bodybuilding, steroids, or performance enhancement. For others, it is treated like a vanity medication for men who simply want to feel younger. But this round-table conversation makes a much more important point: testosterone is not a fringe hormone. It is a major signal of men’s health.
That does not mean every man should be on testosterone. It does not mean low energy, low libido, erectile dysfunction, depression, weight gain, or loss of muscle are always caused by low testosterone. One of the strongest points in this discussion is actually the opposite: these symptoms require a broader evaluation. A man with fatigue and sexual dysfunction might need his testosterone checked, but he may also need thyroid testing, metabolic labs, depression screening, sleep evaluation, medication review, and cardiovascular risk assessment.
That is the point.
Testosterone is not the whole story. But it is often part of the story, and for too long, many physicians have been trained to fear it, ignore it, or treat it as optional.
This conversation is really about updating that framework. Low testosterone is not just a sexual health issue. Erectile dysfunction is not just a prescription issue. Male infertility is not just a reproduction issue. These are often “check engine lights” for deeper physiology.
And men need a healthcare system that treats them that way.
Testosterone Is A Health Signal, Not Just A Sex Hormone
One of the most important ideas in this discussion is that testosterone should be viewed as a marker of overall male health.
That is a shift from how many people still think about it. Testosterone is usually associated with libido, erections, muscle, motivation, and physical performance. All of that is real. But the panel makes the case that testosterone also sits at the intersection of metabolic health, cardiovascular health, mood, bone density, anemia, fertility, and body composition.
A man with low testosterone may present with low libido, erectile dysfunction, fatigue, depressed mood, poor recovery, loss of strength, increased abdominal fat, or lower motivation. But the question should not be, “How do we raise the number as fast as possible?” The first question should be, “Why is this happening?”
This is where the diagnosis matters. The Endocrine Society recommends diagnosing hypogonadism only when men have symptoms and signs of testosterone deficiency plus consistently low testosterone levels, and they recommend confirming low values with repeat morning testing. The American Urological Association similarly states that the diagnosis requires both low testosterone and relevant symptoms or signs, with a total testosterone below 300 ng/dL used as a reasonable cut-off to support the diagnosis.
But the panel also brings up a clinical reality: a single number does not perfectly describe the person sitting in front of you.
Some men feel well at 400 ng/dL. Others feel terrible at 400. Some of that may relate to free testosterone, sex hormone-binding globulin, body size, androgen receptor sensitivity, underlying illness, sleep, obesity, medications, or simply where that man lived hormonally when he was younger. This is why the AUA’s treatment target is not merely “above 300,” but the middle tertile of the normal physiologic range, roughly 450 to 600 ng/dL.
The panel also pushes back on the idea that testosterone decline is simply “normal aging.” Aging does play a role, but it is not the whole story. Obesity, insulin resistance, diabetes, sleep apnea, chronic illness, medications, and metabolic dysfunction can all push testosterone down.
A large model drawn from thirteen studies shows that total testosterone peaks at about 15.4 nmol/L (≈445 ng/dL) around age 19, and by age 40, averages only modestly lower at 13.0 nmol/L (≈375 ng/dL). From there, levels stay relatively flat through old age, with variation rather than steady decline being the more striking trend.
Reviews of obesity-related secondary hypogonadism describe obesity as one of the major drivers of low testosterone in men, with mechanisms involving insulin resistance, low SHBG, inflammation, leptin signaling, and disruption of the hypothalamic-pituitary-gonadal axis.
This is why low testosterone should not be dismissed. It may be a clue that something deeper is off.
The Safety Conversation Has Changed
For decades, testosterone therapy carried enormous stigma because of three major fears: prostate cancer, heart attacks, and abuse.
Those fears still shape clinical practice. Many primary care physicians are hesitant to prescribe testosterone because they worry it will cause prostate cancer, worsen urinary symptoms, raise cardiovascular risk, or create legal and monitoring headaches. The panel’s point is not that testosterone is risk-free. It is that the old fears are not aligned with the current evidence.
The prostate cancer fear is one of the clearest examples. The older idea was that testosterone “feeds the fire” of prostate cancer. But the modern model is more nuanced. The prostate appears sensitive to testosterone at very low concentrations, but once androgen receptors are sufficiently stimulated, additional testosterone does not seem to keep producing a linear increase in prostate growth or PSA. This is often called the saturation model.
Current evidence does not support the idea that testosterone therapy causes new prostate cancer in appropriately selected men, and the TRAVERSE prostate safety analysis found no significant increase in prostate cancer or high-grade prostate cancer among men treated with testosterone gel compared with placebo.
The cardiovascular story has also changed. In 2023, the TRAVERSE trial evaluated testosterone therapy in more than 5,000 men with hypogonadism and preexisting or high cardiovascular risk. Testosterone therapy was noninferior to placebo for major adverse cardiovascular events, meaning it did not increase the primary cardiovascular endpoint compared with placebo in that high-risk population.
That trial was consequential. In February 2025, the FDA issued class-wide testosterone labeling changes, removing language suggesting an increased risk of adverse cardiovascular outcomes based on the TRAVERSE results, while also requiring labeling around increased blood pressure for testosterone products where appropriate.
This is a big deal.
It does not mean testosterone should be used casually, but it does mean the conversation should be more accurate. There is a major difference between medically supervised testosterone therapy designed to restore physiologic levels and supraphysiologic anabolic steroid use. Those are not the same thing.
Monitoring still matters. Testosterone can raise hematocrit, which means more red blood cells in circulation. It can influence blood pressure in some men. It can suppress sperm production. It can change estradiol levels. It requires follow-up, appropriate labs, and a clinician who understands the timing of blood draws relative to injections, gels, pellets, or other delivery methods.
The panel also makes a subtle but important point about estrogen. Earlier generations of clinicians sometimes treated estradiol in men like a problem to eliminate. That was a mistake. Men need estrogen too because estradiol plays a role in libido, sexual function, bone health, and other physiologic systems.
Basically, good testosterone care is not giving the shot and moving on, but instead getting a diagnosis, personalization, monitoring, fertility planning, and ongoing clinical judgment.
Testosterone And Metabolism Are Deeply Connected
Another major theme in this discussion is the relationship between testosterone, obesity, diabetes, and muscle.
This relationship runs in both directions. Excess body fat can lower testosterone. Low testosterone can make it harder to maintain muscle, energy, insulin sensitivity, and body composition. As body fat rises, testosterone often falls, and as testosterone falls, a man may have less energy to train, less muscle to support glucose disposal, more fat accumulation, and a harder time reversing the pattern.
That is the metabolic trap.
The T4DM trial is one of the most important studies here. In this two-year randomized, double-blind, placebo-controlled trial, more than 1,000 men aged 50 to 74 with increased waist circumference, low-normal testosterone, and impaired glucose tolerance or newly diagnosed type 2 diabetes participated in a lifestyle program and received either testosterone undecanoate or placebo. Testosterone treatment reduced the proportion of men with type 2 diabetes beyond the effect of lifestyle alone.
This obviously does not make testosterone a first-line diabetes drug. It does not replace nutrition, training, weight loss, sleep, or GLP-1 therapy when indicated. But it does reinforce the panel’s central argument that testosterone is metabolically relevant.
This becomes even more important in the GLP-1 era.
GLP-1 medications are changing obesity medicine, and the panel is clearly in favor of using them when appropriate. But rapid weight loss creates a new priority: preserving muscle. Weight loss is never just “weight.” It includes fat mass and some lean mass.
In body composition analyses from major GLP-1 and dual agonist trials, most weight lost is fat, but a measurable portion is lean mass. Tirzepatide data from SURMOUNT-1 show about 75% of lost weight was fat mass and about 25% was lean mass, a proportion similar to many non-drug weight loss interventions.
That is why the solution is not simply “take GLP-1 and eat less.”
The solution is protein, resistance training, adequate sleep, and medical supervision. For some men, especially those with true hypogonadism, testosterone may be part of preserving function, training capacity, and metabolic health. For others, losing weight, improving sleep apnea, reducing alcohol, building muscle, and improving insulin sensitivity may raise testosterone without replacement therapy.
And it is why the panel keeps returning to muscle. If a man loses fat but also loses strength, energy, bone density, and functional capacity, the job is not done. The goal is a healthier, stronger, more capable body.
Men Need A Healthcare System Before Crisis
One of the strongest parts of the conversation is the broader point about men’s health.
Women often enter the healthcare system earlier through gynecology, contraception, pregnancy, fertility, and routine reproductive care. Men often disappear from healthcare after pediatrics and may not show up again until infertility, erectile dysfunction, chest pain, or a crisis forces the issue.
That gap matters.
Erectile dysfunction is a perfect example. ED should not be treated as an isolated plumbing problem. It can be a vascular symptom, a metabolic symptom, a hormonal symptom, a neurologic symptom, a psychological symptom, or some combination of all of these.
A 2019 meta-analysis of 25 studies involving more than 154,000 men found that ED was associated with a 43% increased risk of cardiovascular disease, 59% increased risk of coronary heart disease, 34% increased risk of stroke, and 33% increased risk of all-cause mortality.
That does not mean every man with ED is about to have a heart attack, but it does mean that ED is a reason to look deeper.
Check blood pressure. Check A1c. Check fasting glucose and insulin when appropriate. Check lipids. Ask about sleep apnea, snoring, alcohol, nicotine, cannabis, medications, stress, depression, and training. Check testosterone. Ask what changed and when.
The same principle applies to male infertility. Poor sperm production is not only a fertility issue. Semen quality may be a marker of broader health. In a U.S. cohort of men evaluated for infertility, men with two or more abnormal semen parameters had a 2.3-fold higher risk of death compared with men with normal semen parameters, even after adjustment for current health status.
That is a profound statement. Sperm production is biologically expensive and highly sensitive to heat, hormones, toxicants, inflammation, oxidative stress, illness, and environmental exposure. When it is poor, the question should not only be, “Can we get this couple pregnant?” It should also be, “What does this tell us about the man’s health?”
Varicoceles are one example. A varicocele is an enlargement of veins around the testicle that can impair sperm production, likely in part by increasing testicular temperature. Varicoceles affect up to about 15% of men and are more common in men presenting with infertility. Research suggests varicocele repair may improve testosterone in some men, particularly those with low baseline levels, although it should not be oversold as a universal testosterone fix.
The panel also brings up testicular self-awareness. Testicular cancer is most common in younger men, and the first sign is often a painless lump or swelling. The American Cancer Society does not issue a universal testicular self-exam guideline, but it advises men to be aware of risk and promptly report testicular or scrotal changes, especially lumps. Many clinicians still recommend monthly self-checks after puberty because men need to know what normal feels like so they can recognize when something changes.
This is the bigger message: men need earlier touchpoints, not because they are broken or because every young man needs labs and prescriptions, but because waiting until the system fails is bad medicine.
Action Checklist
Know your baseline. Men should consider checking testosterone earlier in adulthood, ideally when healthy, so future changes have context.
Do not diagnose yourself from one lab. Testosterone should usually be checked in the morning and repeated if low, especially when symptoms are present.
Look beyond total testosterone. Free testosterone, SHBG, LH, FSH, estradiol, prolactin, thyroid, metabolic labs, sleep, medications, and body composition may all matter.
Treat symptoms and physiology, not just a number. A lab value helps guide care, but the person in front of the clinician matters too.
Do not ignore erectile dysfunction. ED can be a cardiovascular, metabolic, hormonal, psychological, or neurologic warning sign. It deserves evaluation, not just a prescription.
Protect fertility before starting testosterone. Exogenous testosterone can suppress sperm production. Younger men or men who may want children should discuss semen analysis, sperm banking, hCG, clomiphene, enclomiphene, or other fertility-preserving options with an experienced clinician.
Understand the difference between therapy and abuse. Medically supervised testosterone therapy aimed at physiologic levels is not the same as supraphysiologic anabolic steroid use.
Monitor hematocrit and blood pressure. Testosterone can increase red blood cell production and may affect blood pressure in some men, so follow-up matters.
Do not crush estradiol. Men need estrogen for sexual function, bone health, and overall physiology.
If you are using a GLP-1, protect muscle aggressively. Prioritize protein, resistance training, and sleep. Weight loss without muscle preservation is an incomplete strategy.
Check your testicles. Know what normal feels like and report lumps, swelling, size changes, heaviness, or persistent discomfort.
Take male infertility seriously. Poor semen quality can be a clue about broader health, not just a reproductive inconvenience.
Get a second opinion when needed. If you have symptoms, consistently low or borderline-low testosterone, and your clinician is uncomfortable managing it, ask for referral to a urologist, endocrinologist, or experienced men’s health physician.
The core message from this round table is simple: testosterone is not the whole story, but it is too important to ignore. Men deserve a healthcare model that sees sexual function, fertility, hormones, metabolism, and cardiovascular risk as connected systems, because that is exactly how the body works.
