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Bioavailable Estradiol Metrics

Meaning

Bioavailable Estradiol Metrics represent the clinical measurement of the fraction of estradiol (E2) that is unbound to sex hormone-binding globulin (SHBG) and albumin, thus remaining freely available to exert biological effects on target tissues. This metric provides a more accurate assessment of estrogenic activity than total estradiol alone, which includes the inactive, bound portion. Clinicians rely on these metrics to precisely evaluate the functional estrogen status in patients, particularly those undergoing hormone replacement therapy. Understanding the bioavailable fraction is essential for effective hormonal dosimetry and mitigating the risk of under- or over-treatment.