酢酸メレンゲストロール CAS:2919-66-6

Melengestrol acetate (宿, ウーサン), sometimes abbreviated as MGA, is a steroidal progestin and antineoplastic agent.It is not approved for use in humans, and is instead used as a feed additive to promote growth in cattle, a purpose it is licensed for in the United States and Canada.It is an acetate ester of melengestrol, which in contrast, is not used in either animals or humans.

Progestogens are synthetic forms of the naturally occurring hormone, progesterone. Progesterone is produced by the corpus luteum . By negative feedback, it reduces pituitary function, thus preventing a female from coming into heat. When administered in conjunction with a luteolytic agent, such as PGF2a or estradiol valerate, progestogens can provide an effective means of resetting the cow's physiological clock. If the progestogen is administered for several days, an artificial corpus luteum can in effect be installed, which can be removed at the producer's discretion.