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Bioactive Testosterone Fractions

Meaning

Bioactive Testosterone Fractions represent the specific, unbound portions of the total circulating testosterone pool that are structurally available to interact with androgen receptors and elicit a biological response in target tissues. This critical measurement includes free testosterone and the testosterone weakly bound to the albumin protein, which can rapidly dissociate for cellular uptake. Assessing these fractions provides a more accurate and clinically relevant indicator of androgenic status than total testosterone alone, especially when Sex Hormone-Binding Globulin (SHBG) levels are altered. These fractions are the true drivers of male and female physiological vigor.