What is the Origin of Free Hormone Quantification?

The term originates from clinical chemistry and endocrinology, arising from the recognition that most steroid and thyroid hormones are largely protein-bound and thus biologically inert. The need for a more accurate metric of tissue exposure drove the development of specialized assays for the free fraction.

What is the Mechanism of Free Hormone Quantification?

The free hormone hypothesis dictates that only the unbound hormone is available to interact with intracellular or membrane receptors. Quantification is achieved through highly sensitive laboratory techniques, such as equilibrium dialysis or mass spectrometry, which physically separate the free fraction from the bound fraction. This mechanism directly assesses the hormone available to exert its effect on the cellular machinery.

Free Hormone Quantification ∞ Area

Free Hormone Quantification

Meaning

Free hormone quantification is the precise measurement of the biologically active fraction of a hormone in the circulation, which is not bound to carrier proteins like Sex Hormone-Binding Globulin (SHBG) or albumin. This unbound portion is the only form capable of diffusing into target tissues and eliciting a physiological response. Clinical practice increasingly relies on this measurement as it offers a more accurate reflection of a patient’s functional hormonal status compared to total hormone levels.