Progesterone is an endogenous steroid and progestogen sex hormone involved in the menstrual cycle, pregnancy, and embryogenesis of humans and other species. It belongs to a group of steroid hormones called the progestogens and is the major progestogen in human physiology. Chemically designated as pregn-4-ene-3,20-dione (molecular formula C21H30O2, molecular weight 314.47 g/mol), progesterone is synthesized from cholesterol via pregnenolone and signals primarily through intranuclear progesterone receptors PR-A and PR-B to regulate gene transcription in reproductive tissues. Key pharmacokinetic and physicochemical notes include low aqueous solubility, substantial first pass hepatic metabolism by reduction and conjugation to polar metabolites, lipophilicity that facilitates tissue distribution, and clinical use in luteal support, contraception and hormone replacement therapy.
Parent: Progesterone
Parent: Progesterone
Parent: Progesterone
Parent: Progesterone
Parent: Progesterone
Parent: Progesterone
Parent: Progesterone
Parent: Progesterone
Parent: Progesterone
Parent: Progesterone
Parent: Progesterone
Parent: Progesterone
Parent: Progesterone
Typical active pharmaceutical ingredient quality control targets for progesterone specify a high assay and tight control of related substances to ensure safety and efficacy. A common specification framework is assay by validated HPLC method at or above 97.0 percent of declared potency, individual related compounds controlled to 0.1 to 0.5 percent by area or weight percent, and total related substances limited to 1.0 to 2.0 percent, depending on the manufacturing route and regulatory requirements. Frequently monitored related compounds and impurities include dihydroprogesterone isomers (for example 5alpha and 5beta dihydroprogesterone), 20alpha-dihydroprogesterone, 17alpha-hydroxyprogesterone, pregnane-type rearrangement products and process- or solvent-derived residuals; limits are established based on toxicological assessment and validated impurity identification.
Progesterone prepares the endometrium for embryo implantation, supports early pregnancy by maintaining a secretory uterine lining, modulates menstrual cycle timing through feedback on the hypothalamic pituitary axis, and influences mammary gland differentiation; it also has central nervous system effects mediated by metabolite interaction with GABAergic systems.
Low progesterone can result in luteal phase deficiency, irregular menstrual cycles, difficulty sustaining early pregnancy, increased risk of miscarriage in some contexts, and symptoms such as menstrual spotting, mood changes and infertility related complaints; clinical evaluation typically includes serum assays timed to the luteal phase and assessment of ovulation.
Excessively high progesterone, which is uncommon outside of supplementation, can cause symptoms such as sedation, breast tenderness, fluid retention, and mood changes; in endogenous cases high levels may indicate luteal cysts or specific adrenal or ovarian pathologies and should be investigated with endocrine testing and imaging as indicated.
Progesterone and its neuroactive metabolites such as allopregnanolone positively modulate GABA A receptor activity in the brain, producing anxiolytic and calming effects that can improve mood and sleep in many individuals, which is why it is sometimes colloquially referred to as the happy hormone.
