Testosterone (Total and Free)
The primary male sex hormone, reported as total testosterone in ng/dL and free (bioavailable) testosterone in pg/mL. Optimal range: 264-916 ng/dL total testosterone (harmonized reference range, healthy non-obese men 19-39).
What it measures
The primary male sex hormone, reported as total testosterone in ng/dL and free (bioavailable) testosterone in pg/mL. Measure fasting in the morning, when levels peak.
Why it matters
Testosterone governs muscle mass, bone density, libido, mood, and energy in men. Levels below the harmonized reference range with symptoms define hypogonadism, which is treatable.
Optimal ranges
Sourced targets, not just lab reference ranges. Lab ranges describe the population; these describe where the evidence says you want to be.
| Range | Context |
|---|---|
| 264-916 ng/dL total testosterone (harmonized reference range, healthy non-obese men 19-39) | Harmonized reference range from four US/European cohorts cross-calibrated to a CDC reference method (Travison et al., JCEM 2017). No published longevity optimum exists; clinicians generally aim mid-normal in symptomatic men. |
How to improve it
- 1
Resistance training and adequate sleep
- 2
Lose excess body fat, which converts testosterone to estrogen
- 3
Ensure adequate calories, zinc, and vitamin D
- 4
Test twice in the morning before considering therapy; see a doctor
Connected to
Goals
Ingredients
Longevity Lab Report
Move your Testosterone (Total and Free), know the evidence.
New research on testosterone (total and free) and what moves it, in one email a week. Free.
Educational information, not medical advice. Talk to your doctor before acting on any biomarker result.