What is "progestogen"

n. (context steroid hormone steroid drug English) (alternative spelling of progestagen English)

n. any of a group of steroid hormones that have the effect of progesterone [syn: progestin]

Progestogens (also sometimes spelled progestagens or gestagens) are a class of steroid hormones that bind to and activate the progesterone receptor (PR). The most important progestogen in the body is progesterone (P4). Other endogenous progestogens include 17α-hydroxyprogesterone, 20α-dihydroprogesterone, 5α-dihydroprogesterone, 11-deoxycorticosterone, and 5α-dihydrodeoxycorticosterone. Synthetic progestogens are generally referred to as progestins. The terms progesterone, progestogen, and progestin are mistakenly used interchangeably both in the scientific literature and in clinical settings. While the progestins are structural analogues of the endogenous progestogens, they are not functional analogues.

The progestogens are one of the five major classes of steroid hormones, in addition to the androgens, estrogens, glucocorticoids, and mineralocorticoids, as well as the neurosteroids. All progestogens are characterized by their basic 21-carbon skeleton, called a pregnane skeleton (C21). In similar manner, the estrogens possess an estrane skeleton (C18), and androgens, an andrane skeleton (C19).

The progestogens are named for their function in maintaining pregnancy (i.e., progestational), although they are also present at other phases of the estrous and menstrual cycles.