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Bioavailable Estradiol

Meaning

Bioavailable estradiol represents the fraction of the potent estrogen, estradiol, that is circulating in the bloodstream either unbound to any protein or loosely bound to albumin. This specific, non-SHBG-bound portion is the physiologically active hormone capable of rapidly diffusing across cell membranes to interact with target receptors. It provides a more accurate assessment of the true estrogenic effect on peripheral tissues than total estradiol measurements alone. This metric is essential for tailoring effective and safe hormone replacement therapy.