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Hormone Availability

Meaning

Hormone Availability refers to the concentration of a specific hormone in the circulation that is unbound to carrier proteins and therefore biologically active and capable of interacting with its target cell receptors. This “free” fraction is the true measure of hormonal impact on tissues and is often a more critical clinical metric than the total hormone level. Low availability, even with high total hormone levels, can lead to symptoms of deficiency due to excessive binding by proteins like Sex Hormone Binding Globulin (SHBG). Optimizing availability is paramount for effective hormonal signaling.