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Bioactive Hormone Forms

Meaning

These refer specifically to the fraction of a hormone circulating in the bloodstream that is unbound to carrier proteins and therefore capable of interacting with target cell receptors to elicit a biological response. This free, unbound portion is the physiologically active component responsible for driving endocrine effects, unlike the larger, protein-bound fraction which serves as a circulating reservoir. Clinical assessment of hormonal status must often consider this bioactive fraction for an accurate picture of tissue-level exposure and function. Optimizing health means ensuring adequate levels of these functional forms.