DisclosureWe earn commission on partner links; ranking is set by our evidence-based methodology — not advertisers. Read policy
The fraction of testosterone not bound to proteins and available to tissues — often more telling than total.
Most testosterone in the blood is bound to SHBG and albumin; only the small unbound (“free”) fraction is readily available to tissues. Free testosterone can better reflect androgen status than total testosterone, especially when SHBG is abnormal. It is usually estimated from total testosterone, SHBG, and albumin rather than measured directly.