Progesterone

Progesterone is a C-21 steroid hormone produced by the corpus luteum, placenta, and adrenal cortex, playing central roles in the female reproductive cycle, thermogenesis, and neuroactive signalling as a precursor to allopregnanolone. Salivary progesterone measurement is well-validated in reproductive endocrinology and sports science, reflecting the bioavailable free fraction relevant to menstrual phase-dependent variations in exercise performance, recovery, and injury risk. Elliott-Sale et al. (2020) and Loucks (1998) established salivary progesterone monitoring as essential in female athlete health and relative energy deficiency assessment.