A steroid is a biologically active organic compound with four rings arranged in a specific molecular configuration. Steroids have two principal biological functions: as important components of cell membranes that alter membrane fluidity; and as signaling molecules. Hundreds of steroids are found in plants, animals and fungi. All steroids are manufactured in cells from the sterols lanosterol (opisthokonts) or cycloartenol (plants). Lanosterol and cycloartenol are derived from the cyclization of the triterpene squalene.
Nandrolone, also known as 19-nortestosterone, is an androgen and anabolic steroid (AAS) which is used in the form of esters such as nandrolone decanoate and nandrolone phenylpropionate. Nandrolone esters are used in the treatment of anemias, cachexia, osteoporosis, breast cancer, and for other indications. They are not used by mouth and instead are given by injection into muscle or fat.
Norethisterone, also known as norethindrone and sold under many brand names, is a progestin medication used in birth control pills, menopausal hormone therapy, and for the treatment of gynecological disorders. The medication is available in both low-dose and high-dose formulations and both alone and in combination with an estrogen. It is used by mouth or, as norethisterone enanthate, by injection into muscle.
Trestolone, also known as 7α-methyl-19-nortestosterone (MENT), is an experimental androgen/anabolic steroid (AAS) and progestogen medication which has been under development for potential use as a form of hormonal birth control for men and in androgen replacement therapy for low testosterone levels in men but has never been marketed for medical use. It is given as an implant that is placed into fat. As trestolone acetate, an androgen ester and prodrug of trestolone, the medication can also be given by injection into muscle.
Trestolone acetate is a synthetic and injected anabolic–androgenic steroid (AAS) and a derivative of nandrolone (19-nortestosterone) which was never marketed. It is an androgen ester – specifically, the C17 acetate ester of trestolone. The medication was first described in 1963.
Mibolerone, also known as dimethylnortestosterone (DMNT) and sold under the brand names Cheque Drops and Matenon, is a synthetic, orally active, and extremely potent anabolic–androgenic steroid (AAS) and a 17α-alkylated nandrolone (19-nortestosterone) derivative which was marketed by Upjohn for use as a veterinary drug. It was indicated specifically as an oral treatment for prevention of estrus (heat) in adult female dogs.
Noretynodrel, or norethynodrel, sold under the brand name Enovid among others, is a progestin medication which was previously used in birth control pills and in the treatment of gynecological disorders but is now no longer marketed. It was available both alone and in combination with an estrogen. The medication is taken by mouth.
Quingestanol acetate, sold under the brand names Demovis and Pilomin among others, is a progestin medication which was used in birth control pills but is no longer marketed. It is taken by mouth.
19-Norprogesterone, also known as 19-norpregn-4-ene-3,20-dione, is a steroidal progestin and close analogue of the sex hormone progesterone, lacking only the C19 methyl group of that molecule. It was first synthesized in 1944 in the form of a mixture that also included unnatural stereoisomers of progesterone, and this mixture was found to be at least equivalent to progesterone in terms of progestogenic activity. Subsequent investigations revealed that 17-isoprogesterone and 14-iso-17-isoprogesterone are devoid of progestogenic activity. 19-Norprogesterone was resynthesized in 1951 with an improved method, and was confirmed to be the component of the mixture synthesized in 1944 that was responsible for its progestogenic activity. In 1953, a paper was published showing that 19-norprogesterone possessed 4- to 8-fold the activity of progesterone in the Clauberg assay in rabbits, and at the time of this discovery, 19-norprogesterone was the most potent progestogen known.
A progestogen ester is an ester of a progestogen or progestin. The prototypical progestogen is progesterone, an endogenous sex hormone. Esterification is frequently employed to improve the pharmacokinetics of steroids, including oral bioavailability, lipophilicity, and elimination half-life. In addition, with intramuscular injection, steroid esters are often absorbed more slowly into the body, allowing for less frequent administration. Many steroid esters function as prodrugs.
Dimethandrolone (DMA), also known by its developmental code name CDB-1321, is an experimental androgen/anabolic steroid (AAS) and progestogen medication which is under investigation for potential clinical use.
11β-Methyl-19-nortestosterone (11β-MNT) is a synthetic and orally active anabolic–androgenic steroid (AAS) and a derivative of nandrolone (19-nortestosterone) which was developed by the Contraceptive Development Branch (CDB) of the National Institute of Child Health and Human Development (NICHD) and has not been marketed at this time.
5α-Dihydronorethisterone is a major active metabolite of norethisterone (norethindrone). Norethisterone is a progestin with additional weak androgenic and estrogenic activity. 5α-DHNET is formed from norethisterone by 5α-reductase in the liver and other tissues.
17α-Allyl-19-nortestosterone, also known as 3-ketoallylestrenol or as 17α-allylestr-4-en-17β-ol-3-one, is a progestin which was never marketed. It is a combined derivative of the anabolic–androgenic steroid and progestogen nandrolone (19-nortestosterone) and the antiandrogen allyltestosterone (17α-allyltestosterone). The drug is a major active metabolite of allylestrenol, which is thought to be a prodrug of 17α-allyl-19-nortestosterone.
The structure–activity relationships (SAR) of anabolic steroids (AAS) have been extensively studied.
18-Methylsegesterone acetate is a progestin medication of the 19-norprogesterone group which was never marketed. It was first described in a patent in 1997 and then in a literature paper in 2003. 18-Methyl-SGA is the C18 methyl or C13β ethyl derivative of segesterone acetate, and shows 3 to 10 times the progestogenic potency of SGA in bioassays. This is analogous to the case of the 19-nortestosterone progestin norethisterone and its 18-methyl derivative levonorgestrel, the latter showing substantially increased potency relative to the former similarly. As SGA is already one of the most potent progestins to have been developed, with 100-fold the potency of progesterone and 10-fold the potency of levonorgestrel in bioassays, 18-methyl-SGA is an extremely potent progestogen, among if not the most potent known.
