What type of molecule is progesterone

Steroids are a special kind of fat molecule with a four-ringed, carbon atom backbone or core, like their cholesterol predecessor.

A series of chemical reactions, spurred by proteins called enzymes, remove and add groups to cholesterol's core. These actions transform it first into the steroid pregnenolone, the main precursor of the sex hormones, and then into progesterone and other progestins. In humans and other vertebrates, progestins are made primarily in the female ovaries and male testes.

Progesterone is the most abundant and potent progestin in four-legged vertebrates. The most potent progestins in fish are alphabeta-dihydroxyprogesterone and alphabetatrihydroxyprogesterone. These hormones trigger the process of final maturation in fish eggs and sperm. Many invertebrates can synthesize progesterone but it is not known if it functions as a hormone in these animals. Birth control, hormone replacement therapies, cancer drugs, and other pharmaceuticals contain synthetic progestins.

These manufactured hormones may not produce the same broad actions as natural progestins and can sometimes counteract androgens giving men female characteristics as can natural progesterone. Some progestins used alone or in combination with synthetic estrogens in contraceptives are norethindrone, norgestrel, and ethynodiol diacetate.

Artificial progestins such as medroxyprogesterone acetate and norethindrone are used in breast and endometrial cancer treatment. Like all steroid hormones, progestins produce effects by docking with receptors on the cell's membrane surface or inside the cell in the liquid cytoplasm. Receptor binding triggers different chemical signaling systems depending on receptor location. Progestins have broad effects in backboned animals.

One critical role is as a building block for all other steroid hormones, including androgens and estrogens. Mus musculus NCBI:txid Homo sapiens NCBI:txid See: DOI. Roles Classification. Biological Role s :. Application s :. Manual Xrefs. Registry Numbers. Last Modified. Cell and elements:. Tissue and substructures:. Organ and components:. Biofluid and excreta:. Naturally occurring process:. Biological process:.

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