Diosgenin
Steroidal sapogenin extracted from wild yam and fenugreek, used by industry as a synthesis precursor for progesterone and cortisone. Conversion to progesterone occurs only in a laboratory, never in the human body: this distinction explains why yam creams do not contain bioavailable progesterone.
Never use a dietary supplement without the advice of a healthcare professional. Overdoses as well as deficiencies are not without risk.