Understanding Total Testosterone: Normal vs Optimal Ranges

?What is Total Testosterone?

Total testosterone measures all testosterone in the blood — both bound (to SHBG and albumin) and free. It is the primary male sex hormone produced by the testes (Leydig cells), with smaller amounts from the adrenal glands. Testosterone regulates muscle mass, bone density, libido, red blood cell production, mood, and energy.

!Why It Matters

Low total testosterone (hypogonadism) causes fatigue, reduced libido, erectile dysfunction, muscle loss, depression, and osteoporosis. High testosterone in women causes virilisation and is associated with polycystic ovary syndrome (PCOS). In men, very high levels can indicate anabolic steroid use or adrenal/testicular tumours.

Reference Ranges

Lab normal ranges may vary between laboratories. Optimal and longevity targets are based on research literature and should be interpreted with your physician.

Symptoms of Imbalance

• Low T: fatigue, low libido, erectile dysfunction, reduced muscle mass, depression, increased body fat
• High T in women: acne, excess body hair, irregular periods, deepened voice

How to Improve Your Levels

• 1Optimise sleep — 70% of testosterone is produced during sleep; 7–9 hours per night is essential
• 2Resistance training and HIIT exercise acutely and chronically raise testosterone
• 3Lose excess body fat — adipose tissue converts testosterone to oestrogen via aromatase
• 4Reduce stress and manage cortisol — chronic stress suppresses testosterone
• 5Ensure adequate zinc, vitamin D, and magnesium intake
• 6Testosterone replacement therapy (TRT) under specialist supervision if clinically deficient

When to Test

Morning fasting sample (testosterone peaks at 8 AM); baseline at age 30+; annually if symptomatic or on TRT.

Related Biomarkers