Does SHBG affect free testosterone?
Yes. SHBG binds testosterone in circulation; high SHBG lowers free testosterone, low SHBG raises it. Both are clinically meaningful and reviewed in every hormone optimization workup.
Full answer
Sex Hormone Binding Globulin (SHBG) is a hepatic transport protein that binds testosterone tightly. Free testosterone — the bioactive fraction — is inversely related to SHBG at any given total testosterone. High SHBG lowers free T and contributes to symptoms despite normal total T (often seen with hyperthyroidism, low insulin, hepatic disease). Low SHBG raises free T and is a metabolic marker (insulin resistance, hepatic steatosis, exogenous androgens). SHBG is part of every hormone optimization workup and recalibration.
Educational. Not a substitute for individualized provider review.
- Methodology — Primary source · oMeds
- Reviewed by Dr. Laura Purdy, MD, MBA · Clinical Director, oMeds · Last reviewed 2026-06-03