Where does your testosterone rank for your age?

The median for men aged 18 to 25 is approximately 612 ng/dL, falling to 440 ng/dL by age 76+. The "normal range" widens with age, but the centre of the distribution shifts down. A 50-year-old at 530 ng/dL is at the median for his age. The same value in a 25-year-old is at the 25th percentile.

Yes. Testosterone follows a diurnal rhythm and is highest between 7am and 10am. Afternoon readings can be 20 to 25% lower than morning peaks. The Endocrine Society recommends morning fasting draws for diagnostic accuracy.

Total testosterone measures all circulating testosterone, including the portion bound to sex hormone binding globulin (SHBG) and albumin. Free testosterone is the unbound, biologically active fraction (typically 1 to 3% of total). For most clinical decisions, total testosterone is the primary measurement, but free or bioavailable testosterone may be more informative when SHBG is abnormal.

Testosterone levels and symptoms correlate more loosely than many people assume. SHBG levels, individual androgen receptor sensitivity, and other hormones (oestradiol, cortisol, thyroid) all modulate the symptomatic experience. A symptom-driven evaluation matters as much as the lab number.

Female testosterone is approximately one-twentieth of male levels. The median for women aged 18 to 25 is around 35 ng/dL, declining gradually to about 20 ng/dL post-menopause. Female reference ranges are less well-established than male, with significant variation between labs. Menopausal status is more predictive than age alone.

Yes, modestly. Weight loss in obese men can raise testosterone by 50 to 100 ng/dL on average. Resistance training has small acute effects but no consistent long-term effect on baseline levels in well-trained men. Improved sleep (especially treating sleep apnoea), reducing chronic stress, and moderate alcohol intake all have measurable effects. Effect sizes are typically modest compared to age-related decline.

Testosterone replacement therapy is appropriate for men with confirmed clinically low levels (typically below the age-adjusted 10th percentile) plus consistent symptoms. It is not appropriate for cosmetic boost or for men with normal age-adjusted levels. Risks include polycythaemia, fertility suppression, cardiovascular concerns (debated), and dependence on continued therapy.

TRT safety depends on the individual and requires medical supervision. The TRAVERSE trial (2023, N=5,204 men, NEJM) was the first large randomised controlled trial powered for cardiovascular outcomes and found TRT did not increase the risk of major adverse cardiovascular events compared to placebo in men aged 45 to 80 with pre-existing or high cardiovascular risk. Known risks include erythrocytosis (elevated red blood cell count), acne, potential worsening of sleep apnoea, and suppression of natural testosterone production. TRT is contraindicated in men actively trying to conceive and those with untreated severe sleep apnoea. The benefits, when genuinely low testosterone is confirmed, can include improved energy, libido, mood, bone density, and body composition. The decision should always involve a clinician who reviews your full blood panel, symptoms, and medical history.