Clinical data | |
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Trade names | Halotestin, Ora-Testryl, Ultandren, others |
Other names | Fluoxymestrone; Androfluorene; NSC-12165; 9α-Fluoro-11β-hydroxy-17α-methyltestosterone; 9α-Fluoro-17α-methylandrost-4-en-11β,17β-diol-3-one |
AHFS/Drugs.com | Monograph |
MedlinePlus | a682690 |
Pregnancy category |
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Routes of administration | By mouth [1] |
Drug class | Androgen; Anabolic steroid |
ATC code | |
Legal status | |
Legal status |
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Pharmacokinetic data | |
Bioavailability | Oral: 80% [3] |
Metabolism | Liver (6β-hydroxylation, 5α- and 5β-reduction, 3α- and 3β-keto-oxidation, 11β-hydroxy-oxidation) [4] |
Metabolites | • 5α-Dihydrofluoxymesterone [4] • 11-Oxofluoxymesterone [4] |
Elimination half-life | 9.2 hours [5] [6] |
Excretion | Urine (<5% unchanged) [3] [4] |
Identifiers | |
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CAS Number | |
PubChem CID | |
IUPHAR/BPS | |
DrugBank | |
ChemSpider | |
UNII | |
KEGG | |
ChEBI | |
ChEMBL | |
CompTox Dashboard (EPA) | |
ECHA InfoCard | 100.000.875 |
Chemical and physical data | |
Formula | C20H29FO3 |
Molar mass | 336.447 g·mol−1 |
3D model (JSmol) | |
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Fluoxymesterone, sold under the brand names Halotestin and Ultandren among others, is an androgen and anabolic steroid (AAS) medication which is used in the treatment of low testosterone levels in men, delayed puberty in boys, breast cancer in women, and anemia. [1] It is taken by mouth. [1]
Side effects of fluoxymesterone include symptoms of masculinization like acne, increased hair growth, voice changes, and increased sexual desire. [1] It can also cause liver damage and cardiovascular side effects like high blood pressure. [1] [7] [8] The drug is a synthetic androgen and anabolic steroid and hence is an agonist of the androgen receptor (AR), the biological target of androgens like testosterone and dihydrotestosterone (DHT). [1] [9] It has strong androgenic effects and moderate anabolic effects, which make it useful for producing masculinization. [1] [10]
Fluoxymesterone was first described in 1956 and was introduced for medical use in 1957. [1] [11] In addition to its medical use, fluoxymesterone is used to improve physique and performance. [1] The drug is a controlled substance in many countries and so non-medical use is generally illicit. [1]
Fluoxymesterone is or has been used in the treatment of hypogonadism, delayed puberty, and anemia in males and the treatment of breast cancer in women. [1] [12] It is specifically approved in one or more countries for the treatment of hypogonadism in men, delayed puberty in boys, and breast cancer in women. [13] Current prescribing guidelines in the United States list only the treatment of androgen deficiency in males and breast cancer in females as indications. [1]
Fluoxymesterone is less effective in inducing masculinization than testosterone, but is useful for maintaining established masculinization in adults. [14]
Route | Medication | Major brand names | Form | Dosage |
---|---|---|---|---|
Oral | Testosterone a | – | Tablet | 400–800 mg/day (in divided doses) |
Testosterone undecanoate | Andriol, Jatenzo | Capsule | 40–80 mg/2–4× day (with meals) | |
Methyltestosterone b | Android, Metandren, Testred | Tablet | 10–50 mg/day | |
Fluoxymesteroneb | Halotestin, Ora-Testryl, Ultandren | Tablet | 5–20 mg/day | |
Metandienone b | Dianabol | Tablet | 5–15 mg/day | |
Mesterolone b | Proviron | Tablet | 25–150 mg/day | |
Sublingual | Testosterone b | Testoral | Tablet | 5–10 mg 1–4×/day |
Methyltestosterone b | Metandren, Oreton Methyl | Tablet | 10–30 mg/day | |
Buccal | Testosterone | Striant | Tablet | 30 mg 2×/day |
Methyltestosterone b | Metandren, Oreton Methyl | Tablet | 5–25 mg/day | |
Transdermal | Testosterone | AndroGel, Testim, TestoGel | Gel | 25–125 mg/day |
Androderm, AndroPatch, TestoPatch | Non-scrotal patch | 2.5–15 mg/day | ||
Testoderm | Scrotal patch | 4–6 mg/day | ||
Axiron | Axillary solution | 30–120 mg/day | ||
Androstanolone (DHT) | Andractim | Gel | 100–250 mg/day | |
Rectal | Testosterone | Rektandron, Testosteronb | Suppository | 40 mg 2–3×/day |
Injection (IM or SC ) | Testosterone | Andronaq, Sterotate, Virosterone | Aqueous suspension | 10–50 mg 2–3×/week |
Testosterone propionate b | Testoviron | Oil solution | 10–50 mg 2–3×/week | |
Testosterone enanthate | Delatestryl | Oil solution | 50–250 mg 1x/1–4 weeks | |
Xyosted | Auto-injector | 50–100 mg 1×/week | ||
Testosterone cypionate | Depo-Testosterone | Oil solution | 50–250 mg 1x/1–4 weeks | |
Testosterone isobutyrate | Agovirin Depot | Aqueous suspension | 50–100 mg 1x/1–2 weeks | |
Testosterone phenylacetate b | Perandren, Androject | Oil solution | 50–200 mg 1×/3–5 weeks | |
Mixed testosterone esters | Sustanon 100, Sustanon 250 | Oil solution | 50–250 mg 1×/2–4 weeks | |
Testosterone undecanoate | Aveed, Nebido | Oil solution | 750–1,000 mg 1×/10–14 weeks | |
Testosterone buciclate a | – | Aqueous suspension | 600–1,000 mg 1×/12–20 weeks | |
Implant | Testosterone | Testopel | Pellet | 150–1,200 mg/3–6 months |
Notes: Men produce about 3 to 11 mg of testosterone per day (mean 7 mg/day in young men). Footnotes:a = Never marketed. b = No longer used and/or no longer marketed. Sources: See template. |
Route | Medication | Major brand names | Form | Dosage |
---|---|---|---|---|
Oral | Testosterone undecanoate | Andriol, Jatenzo | Capsule | 40–80 mg 1x/1–2 days |
Methyltestosterone | Metandren, Estratest | Tablet | 0.5–10 mg/day | |
Fluoxymesterone | Halotestin | Tablet | 1–2.5 mg 1x/1–2 days | |
Normethandrone a | Ginecoside | Tablet | 5 mg/day | |
Tibolone | Livial | Tablet | 1.25–2.5 mg/day | |
Prasterone (DHEA) b | – | Tablet | 10–100 mg/day | |
Sublingual | Methyltestosterone | Metandren | Tablet | 0.25 mg/day |
Transdermal | Testosterone | Intrinsa | Patch | 150–300 μg/day |
AndroGel | Gel, cream | 1–10 mg/day | ||
Vaginal | Prasterone (DHEA) | Intrarosa | Insert | 6.5 mg/day |
Injection | Testosterone propionate a | Testoviron | Oil solution | 25 mg 1x/1–2 weeks |
Testosterone enanthate | Delatestryl, Primodian Depot | Oil solution | 25–100 mg 1x/4–6 weeks | |
Testosterone cypionate | Depo-Testosterone, Depo-Testadiol | Oil solution | 25–100 mg 1x/4–6 weeks | |
Testosterone isobutyrate a | Femandren M, Folivirin | Aqueous suspension | 25–50 mg 1x/4–6 weeks | |
Mixed testosterone esters | Climacterona | Oil solution | 150 mg 1x/4–8 weeks | |
Omnadren, Sustanon | Oil solution | 50–100 mg 1x/4–6 weeks | ||
Nandrolone decanoate | Deca-Durabolin | Oil solution | 25–50 mg 1x/6–12 weeks | |
Prasterone enanthate a | Gynodian Depot | Oil solution | 200 mg 1x/4–6 weeks | |
Implant | Testosterone | Testopel | Pellet | 50–100 mg 1x/3–6 months |
Notes: Premenopausal women produce about 230 ± 70 μg testosterone per day (6.4 ± 2.0 mg testosterone per 4 weeks), with a range of 130 to 330 μg per day (3.6–9.2 mg per 4 weeks). Footnotes:a = Mostly discontinued or unavailable. b = Over-the-counter. Sources: See template. |
Route | Medication | Form | Dosage | |
---|---|---|---|---|
Oral | Methyltestosterone | Tablet | 30–200 mg/day | |
Fluoxymesterone | Tablet | 10–40 mg 3x/day | ||
Calusterone | Tablet | 40–80 mg 4x/day | ||
Normethandrone | Tablet | 40 mg/day | ||
Buccal | Methyltestosterone | Tablet | 25–100 mg/day | |
Injection (IM or SC ) | Testosterone propionate | Oil solution | 50–100 mg 3x/week | |
Testosterone enanthate | Oil solution | 200–400 mg 1x/2–4 weeks | ||
Testosterone cypionate | Oil solution | 200–400 mg 1x/2–4 weeks | ||
Mixed testosterone esters | Oil solution | 250 mg 1x/week | ||
Methandriol | Aqueous suspension | 100 mg 3x/week | ||
Androstanolone (DHT) | Aqueous suspension | 300 mg 3x/week | ||
Drostanolone propionate | Oil solution | 100 mg 1–3x/week | ||
Metenolone enanthate | Oil solution | 400 mg 3x/week | ||
Nandrolone decanoate | Oil solution | 50–100 mg 1x/1–3 weeks | ||
Nandrolone phenylpropionate | Oil solution | 50–100 mg/week | ||
Note: Dosages are not necessarily equivalent. Sources: See template. |
Fluoxymesterone is available in the form of 2, 5, and 10 mg oral tablets. [15]
Fluoxymesterone is used for physique- and performance-enhancing purposes by competitive athletes, bodybuilders, and powerlifters. [1]
Side effects that have been associated with fluoxymesterone include acne, edema, seborrhea/seborrheic dermatitis, alopecia, hirsutism, voice deepening, virilization in general, flushing, gynecomastia, breast pain, menstrual disturbances, hypogonadism, testicular atrophy, clitoral enlargement, penile enlargement, priapism, increased aggressiveness, prostate enlargement, cardiovascular toxicity, and hepatotoxicity, among others. [1] [16]
Medication | Ratioa |
---|---|
Testosterone | ~1:1 |
Androstanolone (DHT) | ~1:1 |
Methyltestosterone | ~1:1 |
Methandriol | ~1:1 |
Fluoxymesterone | 1:1–1:15 |
Metandienone | 1:1–1:8 |
Drostanolone | 1:3–1:4 |
Metenolone | 1:2–1:30 |
Oxymetholone | 1:2–1:9 |
Oxandrolone | 1:3–1:13 |
Stanozolol | 1:1–1:30 |
Nandrolone | 1:3–1:16 |
Ethylestrenol | 1:2–1:19 |
Norethandrolone | 1:1–1:20 |
Notes: In rodents. Footnotes:a = Ratio of androgenic to anabolic activity. Sources: See template. |
As an AAS, fluoxymesterone is an agonist of the androgen receptor (AR), similarly to androgens like testosterone and DHT. [1] [17] It is a substrate for 5α-reductase like testosterone, and so is potentiated in so-called "androgenic" tissues like the skin, hair follicles, and prostate gland via transformation into 5α-dihydrofluoxymesterone. [1] [17] [4] As such, fluoxymesterone has a relatively poor ratio of anabolic to androgenic activity similarly to testosterone and methyltestosterone. [1] [17] However, fluoxymesterone is nonetheless proportionally less androgenic and more anabolic than methyltestosterone and testosterone. [10]
Fluoxymesterone has been reported to be non-aromatizable due to steric hindrance by its C11β hydroxyl group, [18] and hence is not considered to have a propensity for producing estrogenic effects such as gynecomastia or fluid retention. [1] [19] However, paradoxically, a case report of severe fluoxymesterone-induced gynecomastia exists, and gynecomastia associated with fluoxymesterone has also been reported in other publications, although this may not be due to estrogenic activity. [20] Fluoxymesterone is thought to possess little or no progestogenic activity. [1] [17]
Because of the presence of its 17α-methyl group, the metabolism of fluoxymesterone is impeded, resulting in it being orally active, although also hepatotoxic. [1] [17]
Fluoxymesterone has been found to act as a potent inhibitor of 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2) (IC50 = 60–630 nM), with a potency comparable to that of the 11β-HSD2 inhibitor glycyrrhetinic acid. [7] [8] This action of fluoxymesterone is unique among AAS and is likely related to its 11β-hydroxyl group. [7] 11β-HSD2 is responsible for the inactivation of the glucocorticoids cortisol and corticosterone (into cortisone and 11-dehydrocorticosterone, respectively). [7] [8] Inhibition of 11β-HSD2 by fluoxymesterone may result in mineralocorticoid receptor overactivation and associated side effects such as hypertension and fluid retention, and has been hypothesized to be involved in the cardiovascular and other adverse effects of fluoxymesterone. [7] [8]
Unlike other AAS, fluoxymesterone has structural features in common with corticosteroids, including its C9α fluoro and C11β hydroxyl groups. [21] In relation to this, it has weak (micromolar) but potentially clinically significant affinity for the glucocorticoid receptor. [22]
Fluoxymesterone has approximately 80% oral bioavailability, unlike testosterone, as the C17α methyl group of fluoxymesterone inhibits first-pass metabolism. [3] [1] It has very low affinity for human serum sex hormone-binding globulin (SHBG), less than 5% of that of testosterone and less than 1% of that of DHT. [23] The drug is metabolized in the liver, mainly by 6β-hydroxylation, 5α- and 5β-reduction, 3α- and 3β-keto-oxidation, and 11β-hydroxy-oxidation. [4] Its known active metabolites include 5α-dihydrofluoxymesterone and 11-oxofluoxymesterone. [4] [7] [24] [10] Fluoxymesterone has an elimination half-life of approximately 9.2 hours, which is long relative to that of testosterone. [5] It is eliminated in the urine, with less than 5% excreted unchanged. [3] [4]
Fluoxymesterone, also known as 9α-fluoro-11β-hydroxy-17α-methyltestosterone or as 9α-fluoro-17α-methylandrost-4-en-11β,17β-diol-3-one, is a synthetic androstane steroid and a 17α-alkylated derivative of testosterone (androst-4-en-17β-ol-3-one). [25] [26] It is specifically the derivative of testosterone with a fluorine atom at the C9α position, a hydroxyl group at the C11β position, and a methyl group at the C17α position. [25] [26]
Step one: The first step in the synthesis of fluoxymesterone is the microbiological oxidation of commercially available androstenedione (1.11) by Actinomyces; this introduces a hydroxyl group to the 11α-position (1.12), which is then oxidised to a ketone using Jones' reagent, yielding the 3,11,17-triketone, adrenosterone (1.13). Pyrrolidine then reacts to form an enamine (1.14) by reaction with the 3α-keto group, protecting it from alkylation in a subsequent step. The regioselectivity of pyrrolidine for reaction at the 3α-position occurs inherently in the structure of adrenosterone, due to the position of the sterically bulky methyl groups. In subsequent steps, alkylation of the 17-keto group (1.14) using Grignard reagent, addition of hydride at the 11-position (1.15) and regeneration of the protected 3-keto group yields the starting material (1.16) for the final steps of the fluoxymesterone synthesis. This involves more standard synthetic transformations.
Step two: The 11α-hydroxyl of the starting material (1.16) is sulfonylated by p-toluenesulfonyl chloride; addition of trimethylamine (base) deprotonates the 11α-carbon, yielding an (E2) elimination of tosylate (pka - 5) to give olefin (1.17). Stereospecificity of reaction between olefin and hypobromous acid (HOBr) in base, N-bromosuccinimide (NBS), is determined by the formation of a bromonium intermediate; the electrophilic bromonium cation approaches the ring's less sterically hindered α-face and is attacked by the π-electron density of the alkene. The hydroxide ion then attacks from above the ring (β-face) at the 11-carbon, resulting in a structure (1.18) by the stereospecific addition of hydroxyl and bromine across the double bond. Addition of sodium hydroxide results in deprotonation of the 11α-hydroxyl, and the subsequent structure undergoes an intramolecular SN2 epoxy ring formation. The epoxy ring of the β-epoxide (1.19) is protonated to give an oxironium ion intermediate. In a concerted process, fluoride attacks the ring's α-face from below, as one of the two oxygen-carbon bonds is broken on the opposite face; hence regenerating the 11α-hydroxyl trans to the fluorine substituent. The resulting structure (1.20) is the androgenic steroid, fluoxymesterone.
Detection of halotestin and other such illegal anabolic steroids in sports is achieved by GS-MS identification of urinary excreted anabolic steroids and their metabolites. In a test for halotestin, a dry residue obtained from a urine sample is dissolved in dimethylformamide and a sulfur trioxide-pyridine complex and is heated with 1% potassium carbonate solution. Halotestin and many of its metabolites contain two polar hydroxyl groups, leading to intermolecular hydrogen bonding that increases their boiling point and reduces volatility. In order to attain a gaseous sample for GC-MS, the products of hydrolysis are extracted, dissolved in methanol and derivatised to form volatile trimethylsilyl (TMS) esters by adding N-methyl-N-trimethylsilyl-trifluoroacetamide (MSTFA) and trimethylsilylimidazole (TMSImi). [27]
Fluoxymesterone was first described in 1956 and was introduced for medical use in the United States in 1957. [1] [11] Over time the use of fluoxymesterone has become increasingly controversial and limited. [1]
Fluoxymesterone is the generic name of the drug and its INN , USP , BAN , DCIT , and JAN , while fluoxymestérone is its DCF . [25] [26] [28] [29]
Brand names of fluoxymesterone include Android-F, Androxy, Halotestin, Ora-Testryl, and Ultandren among others. [25] [26] [28] [29]
Fluoxymesterone is one of the few AAS that remains available for medical use in the United States. [30] The others (as of August 2023) are testosterone, testosterone cypionate, testosterone enanthate, testosterone undecanoate, methyltestosterone, and oxymetholone. [30]
Availability of fluoxymesterone aside from the United States remains scarce, but it is marketed in some other countries such as Mexico, Moldova, and Taiwan. [1] [29]
Fluoxymesterone, along with other AAS, is a schedule III controlled substance in the United States under the Controlled Substances Act. [31]
Methyltestosterone, sold under the brand names Android, Metandren, and Testred among others, is an androgen and anabolic steroid (AAS) medication which is used in the treatment of low testosterone levels in men, delayed puberty in boys, at low doses as a component of menopausal hormone therapy for menopausal symptoms like hot flashes, osteoporosis, and low sexual desire in women, and to treat breast cancer in women. It is taken by mouth or held in the cheek or under the tongue.
Oxandrolone is an androgen and synthetic anabolic steroid (AAS) medication to help promote weight gain in various situations, to help offset protein catabolism caused by long-term corticosteroid therapy, to support recovery from severe burns, to treat bone pain associated with osteoporosis, to aid in the development of girls with Turner syndrome, and for other indications. It is taken by mouth. It was sold under the brand names Oxandrin and Anavar, among others.
Oxymetholone, sold under the brand names Anadrol and Anapolon among others, is an androgen and anabolic steroid (AAS) medication which is used primarily in the treatment of anemia. It is also used to treat osteoporosis, HIV/AIDS wasting syndrome, and to promote weight gain and muscle growth in certain situations. It is taken by mouth.
Metandienone, also known as methandienone or methandrostenolone and sold under the brand name Dianabol (D-Bol) among others, is an androgen and anabolic steroid (AAS) medication which is still quite often used because of its affordability and effectiveness for bulking cycles. It is also used non-medically for physique- and performance-enhancing purposes. It is often taken by mouth.
Norethandrolone, sold under the brand names Nilevar and Pronabol among others, is an androgen and anabolic steroid (AAS) medication which has been used to promote muscle growth and to treat severe burns, physical trauma, and aplastic anemia but has mostly been discontinued. It is still available for use in France however. It is taken by mouth.
Mesterolone, sold under the brand name Proviron among others, is an androgen and anabolic steroid (AAS) medication which is used mainly in the treatment of low testosterone levels. It has also been used to treat male infertility, although this use is controversial. 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.
Mestanolone, also known as methylandrostanolone and sold under the brand names Androstalone and Ermalone among others, is an androgen and anabolic steroid (AAS) medication which is mostly no longer used. It is still available for use in Japan however. It is taken by mouth.
Anabolic steroids, also known as anabolic-androgenic steroids (AAS), are a class of drugs that are structurally related to testosterone, the main male sex hormone, and produce effects by binding to the androgen receptor (AR). Anabolic steroids have a number of medical uses, but are also used by athletes to increase muscle size, strength, and performance.
Epitiostanol, sold under the brand name Thiodrol, is an injected antiestrogen and anabolic–androgenic steroid (AAS) of the dihydrotestosterone (DHT) group which was described in the literature in 1965 and has been marketed in Japan as an antineoplastic agent for the treatment of breast cancer since 1977.
Formebolone, also known as formyldienolone, as well as 2-formyl-11α-hydroxy-17α-methyl-δ1-testosterone, is an orally active anabolic-androgenic steroid (AAS) described as an anticatabolic and anabolic drug that is or has been marketed in Spain and Italy. As an AAS, it shows some anabolic activity, though it is inferior to testosterone in terms of potency, but is said to have virtually no androgenic activity. Formebolone counteracts the catabolic effects of potent glucocorticoids like dexamethasone phosphate. A close analogue, roxibolone, shows similar antiglucocorticoid activity to formebolone but, in contrast, is devoid of activity as an AAS.
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.
Methylestradiol, sold under the brand names Ginecosid, Ginecoside, Mediol, and Renodiol, is an estrogen medication which is used in the treatment of menopausal symptoms. It is formulated in combination with normethandrone, a progestin and androgen/anabolic steroid medication. Methylestradiol is taken by mouth.
Ethyltestosterone, or 17α-ethyltestosterone, also known as 17α-ethylandrost-4-en-17β-ol-3-one or 17α-pregn-4-en-17-ol-3-one, is a synthetic, orally active anabolic–androgenic steroid (AAS) of the 17α-alkylated group related to methyltestosterone which was never marketed. Like methyltestosterone, ethyltestosterone is the parent compound of many AAS. Derivatives of ethyltestosterone include norethandrolone, ethylestrenol (ethylnandrol), norboletone, ethyldienolone, tetrahydrogestrinone, bolenol (ethylnorandrostenol), and propetandrol.
Dimethyltrienolone is a synthetic, orally active, and extremely potent anabolic–androgenic steroid (AAS) and 17α-alkylated 19-nortestosterone (nandrolone) derivative which was never marketed for medical use. It has among the highest known affinity of any AAS for the androgen receptors, and has been said to be perhaps the most potent AAS to have ever been developed.
Vinyltestosterone is a synthetic anabolic–androgenic steroid (AAS) that was never marketed. However, two 19-nortestosterone derivatives of vinyltestosterone, norvinisterone (17α-vinyl-19-nortestosterone) and norgesterone, have been marketed. They are used as progestins for female hormonal contraception, rather than as AAS.
Methylhydroxynandrolone, also known as 4-hydroxy-17α-methyl-19-nortestosterone (HMNT), as well as 4,17β-dihydroxy-17α-methylestr-4-en-3-one, is a synthetic, orally active anabolic–androgenic steroid (AAS) and a 17α-alkylated derivative of nandrolone (19-nortestosterone) which was never marketed. It was first described in 1964 and was studied in the treatment of breast cancer, but was not introduced for clinical use. The drug re-emerged in 2004 when it started being sold on the Internet as a "dietary supplement". MOHN joined other AAS as a controlled substance in the United States on 20 January 2005.
Dimethandrolone undecanoate (DMAU), also known by its developmental code name CDB-4521, is an experimental androgen/anabolic steroid (AAS) and progestogen medication which is under development as a potential birth control pill for men. It is taken by mouth, but can also be given by injection into muscle.
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.
The structure–activity relationships (SAR) of anabolic steroids (AAS) have been extensively studied.