A steroid is an organic compound with four fused rings arranged in a specific molecular configuration.
Progestogens, also sometimes written progestagens or gestagens, are a class of natural or synthetic steroid hormones that bind to and activate the progesterone receptors (PR). Progesterone is the major and most important progestogen in the body. The progestogens are named for their function in maintaining pregnancy, although they are also present at other phases of the estrous and menstrual cycles.
Nandrolone, also known as 19-nortestosterone, is an endogenous androgen which exists in the male body at a ratio of 1:50 compared to testosterone. It is also an anabolic steroid (AAS) which is medically 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.
Norgestimate, sold under the brand names Ortho Tri-Cyclen and Previfem among others, is a progestin medication which is used in birth control pills for women and in menopausal hormone therapy. The medication is available in combination with an estrogen and is not available alone. It is taken by mouth.
Steranes constitute a class of tetracyclic triterpanes derived from steroids or sterols via diagenetic and catagenetic degradation, such as hydrogenation. They are found in sediments and sedimentary rocks in nature. Steranes are derivatives of gonane, the steroid nucleus which is also called "cyclopentanoperhydrophenanthrene". They have an androstane skeleton with a side chain at the C-17 carbon. The sterane structure constitutes the core of all sterols. Steranes are widely used as biomarkers for the presence of eukaryotes in past ecosystems because steroids are nearly exclusively produced by eukaryotes. In particular, cholestanes are diagenetic products of cholesterol in animals, while stigmastanes are diagenetic products of stigmasterols in algae and land plants. However, some bacteria are now known to produce sterols and it is inferred that the ultimate origin of sterol biosynthesis is in bacteria. Sterols are produced via protosterols that are direct cyclization compounds of squalene by the catalysis of oxidosqualene cyclase. All known sterols in eukaryotes are enzymatically extensively modified from protosterols, while organisms that only produce protosterols are not known. The oldest record of modified steranes are in sedimentary rocks deposited ca. 720–820 million years ago. In contrast, diagenetic products of protosterols are widely distributed in older Proterozoic rocks and imply the presence of extinct proto-eukaryotes and/or sterol-producing bacteria before the evolution of crown-group eukaryotes.
Norsteroids are a structural class of steroids that have had an atom or atoms removed, biosynthetically or synthetically, from positions of branching off of rings or side chains, or from within rings of the steroid ring system. For instance, 19-norsteroids constitute an important class of natural and synthetic steroids derived by removal of the methyl group of the natural product progesterone; the equivalent change between testosterone and 19-nortestosterone (nandrolone) is illustrated below.
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.
Gestodene, sold under the brand names Femodene and Minulet among others, is a progestin medication which is used in birth control pills for women. It is also used in menopausal hormone therapy. The medication is available almost exclusively in combination with an estrogen. It is taken by mouth.
Norgestrienone, sold under the brand names Ogyline, Planor, and Miniplanor, is a progestin medication which has been used in birth control pills, sometimes in combination with ethinylestradiol. It was developed by Roussel Uclaf and has been registered for use only in France. Under the brand name Planor, it has been marketed in France as 2 mg norgestrienone and 50 μg ethinylestradiol tablets. It is taken by mouth.
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.
Androstane is a C19 steroidal hydrocarbon with a gonane core. Androstane can exist as either of two isomers, known as 5α-androstane and 5β-androstane.
Pregnane, also known as 17β-ethylandrostane or as 10β,13β-dimethyl-17β-ethylgonane, is a C21 steroid and, indirectly, a parent of progesterone. It is a parent hydrocarbon for two series of steroids stemming from 5α-pregnane and 5β-pregnane (17β-ethyletiocholane). It has a gonane core.
Normethandrone, also known as methylestrenolone or methylnortestosterone and sold under the brand name Metalutin among others, is a progestin and androgen/anabolic steroid (AAS) medication which is used in combination with an estrogen in the treatment of amenorrhea and menopausal symptoms in women. 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.
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.
19-Norpregnane, also known as 13β-methyl-17β-ethylgonane, is a norsteroid and the 19-demethyl analogue of pregnane. It is the parent compound of 19-norprogesterone (19-norpregn-4-ene-3,20-dione) and derivatives of it such as the progestins demegestone, gestonorone caproate, nomegestrol acetate, norgestomet, promegestone, segesterone acetate (nestorone), and trimegestone.
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.
5β-Pregnane, also known as 17β-ethyletiocholane or as 10β,13β-dimethyl-17β-ethyl-5β-gonane, is a steroid and a parent compound of a variety of steroid derivatives. It is one of the epimers of pregnane, the other being 5α-pregnane. Derivatives of 5β-pregnane include the naturally occurring steroids 5β-dihydroprogesterone, pregnanolone, epipregnanolone, pregnanediol, and pregnanetriol, and the synthetic steroids hydroxydione, renanolone, ORG-20599, and SAGE-217. These derivatives include metabolites of progesterone and endogenous and synthetic neurosteroids.
Allopregnane, also known as 5α-pregnane or as 10β,13β-dimethyl-17β-ethyl-5α-gonane, is a steroid and a parent compound of a variety of steroid derivatives. It is one of the epimers of pregnane, the other being 5β-pregnane. Derivatives of allopregnane include the naturally occurring steroids allopregnanolone, allopregnanediol, isopregnanolone, and 5α-dihydroprogesterone.
