Such content is not intended to replace an evaluation with a qualified healthcare professional of your choosing and is not intended as medical advice. The information conveyed on the Humanaut Health website is not intended to act as a substitute for professional medical advice, or to diagnose, treat, cure, mitigate or prevent any disease or serious medical condition. • In men, the goal is physiologic replacement with symptom benefit, not maximal lab values. The AUA uses below 300 ng/dL as a reasonable diagnostic cutoff, but treatment targets are individualized and generally aim for physiologic replacement rather than one universal number (Mulhall et al., Journal of Urology, 2018). Interpreting testosterone requires the clinical picture, the treatment method, the testing interval, and the broader symptom and safety profile. That is why good hormone care depends on more than a screenshot of a lab result. In transdermal therapy, timing matters differently. The next challenge in this interesting field of work will be to perform large randomized controlled trials of testosterone replacement in men with coronary artery disease. More importantly, once hypogonadism is diagnosed, replacement therapy has a beneficial anti-ischaemic effect, along with beneficial effects on lipids, glucose metabolism, inflammatory cytokine profiles, lean body mass, blood clotting profiles and patient well-being. However, to our knowledge, there is no evidence supporting a causative role of testosterone supplementation on the levels in the physiological normal range, with the risk of developing prostate cancer. In healthy nonobese men aged 19 to 39, harmonized reference work identified an approximate normal range of 264 to 916 ng/dL, with a median near 531 ng/dL. It helps determine who may qualify for therapy alongside symptoms; it does not mean every treated man should be driven to the same number regardless of response or formulation (Mulhall et al., Journal of Urology, 2018). A woman being treated for hypoactive sexual desire disorder should not be guided by the same lab framework used for male hypogonadism (Bhasin et al., Journal of Clinical Endocrinology & Metabolism, 2018; Parish et al., Climacteric, 2021). Testosterone levels in males naturally decline with age. This is called androgen insensitivity syndrome (AIS) and occurs when someone is genetically male but is insensitive to androgens (male sex hormones). Testosterone deficiency during fetal development doesn’t allow male characteristics to develop normally. The symptoms of low testosterone vary based on your age. But recent studies suggest it’s not just about symptoms. That’s called testosterone deficiency (sometimes called hypogonadism).2 This is normal, but in some men, the drop becomes steep enough to trigger symptoms like low libido, fatigue, muscle loss, and irritability. Only a small amount (around 1–2%) circulates as "free testosterone," which is the form that’s active and available to your body’s tissues, including the heart and blood vessels.2 In the bloodstream, most testosterone is bound to a protein called SHBG (sex hormone-binding globulin). Healthcare providers use synthetic testosterone to treat and manage various medical conditions. "Anabolic" refers to muscle building, and "androgenic" refers to increased male sex characteristics. Natural testosterone is a steroid — an anabolic-androgenic steroid. Testosterone is the main androgen, meaning it stimulates the development of male characteristics. More specifically, both testicles and ovaries produce testosterone. Testosterone is a hormone that your gonads (sex organs) mainly produce. Testosterone is a hormone that your gonads (testicles or ovaries) mainly produce. Your hypothalamus and pituitary gland control the amount of testosterone your gonads (testicles or ovaries) produce and release. Testosterone triggers the development of the male internal and external reproductive organs during fetal development. At around week seven in utero, the sex-related gene on the Y chromosome initiates the development of the testicles in male infants. Even with an abnormally low level that is replicated on a repeat test, the decision to begin testosterone replacement therapy and the proper dose requires a careful conversation with your doctor. Studies estimate the prevalence of symptomatic hypogonadism in men with coronary disease at approximately one-quarter (24%) and that these men have poorer cardiovascular outcomes than those with normal androgen levels. However, it has now been demonstrated in several large longitudinal cohort studies of men with and without coronary disease that low baseline testosterone is a significant risk marker of increased all-cause and cardiovascular mortality. Our view is that this study showed that men with hypogonadism should be treated only with physiological doses of testosterone for true replacement therapy. Despite historical concerns over testosterone therapy in aging males, there is now a large and rapidly increasing body of evidence suggesting that testosterone replenishment in men with cardiovascular disease is safe and effective. But having high cholesterol doesn't mean your testosterone will be high. While the specifics are uncertain, it's possible that androgens also play an important role in normal brain function (including mood, sex drive and cognitive function). If you thought testosterone was only important in men, you'd be mistaken. There may be other important functions of this hormone that have not yet been discovered. Testosterone may also help maintain normal mood. For example, the genitals may not enlarge, facial and body hair may be scant, and the voice may not deepen normally.
