Total VirilityVol. III · Peptide Atlas
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Testosterone

Free Testosterone

The portion of testosterone not bound to proteins, available for your body to use.

What It Measures

Testosterone that is unbound and biologically active in your bloodstream.

Reference Range

5 pg/mLOptimal: 15–25 pg/mL25 pg/mL

Optimal free testosterone is typically 15-25 pg/mL for adult men.

If High

May indicate excess testosterone production or supplementation.

If Low

Even with normal total T, low free T means your body can't use enough testosterone.

Panels That Include Free Testosterone

Total Virility Core Panel$149
Testosterone Focused Panel$99
The Executive Panel$399

Scientific References

A critical evaluation of simple methods for the estimation of free testosterone in serum

Vermeulen A, Verdonck L, Kaufman JM. J Clin Endocrinol Metab (1999); 84(10):3666-3672.

PMID: 10523012

Longitudinal effects of aging on serum total and free testosterone levels in healthy men. Baltimore Longitudinal Study of Aging

Harman SM, Metter EJ, Tobin JD, Pearson J, Blackman MR. J Clin Endocrinol Metab (2001); 86(2):724-731.

PMID: 11158037
For Educational Purposes Only: The health information on this page is for general educational purposes and is not medical advice. Individual results vary based on age, sex, health history, and other factors. Consult your healthcare provider before making decisions based on this information. See full terms.