progestogen One of a group of naturally occurring or synthetic hormones that maintain the normal course of pregnancy. The best known is progesterone. In high doses progestogens inhibit secretion of luteinizing hormone, thereby preventing ovulation, and alter the consistency of mucus in the vagina so that conception tends not to occur. They are therefore used as major constituents of oral contraceptives.

pro·ges·to·gen / prōˈjestəjən/ • n. Biochem. another term for progestin.

progestogen (proh-jest-oh-jĕn) n. one of a group of naturally occurring or synthetic steroid hormones, including progesterone, that maintain the normal course of pregnancy. Progestogens are used to treat premenstrual tension, amenorrhoea, and abnormal bleeding from the uterus. Because they prevent ovulation, progestogens are a major constituent of oral contraceptives and other forms of hormonal contraception.