gestagens, a group of substances with properties of the female sex hormone, progesterone (the hormone of the corpus luteum), and of the products of its metabolism.

Progestin are found in the corpus luteum, the placenta, ovaries, adrenals, and blood of humans and other mammals. The male sex glands also contain a certain amount of progestins. They exert influence on the mucous membrane of the uterus during pregnancy, ensuring normal development of the embryo. Substances exhibiting progestin-like activity have been obtained by chemical synthesis. Some of them (progesterone, pregnin) are used in medicine.