Metenolone, or methenolone, is an androgen and anabolic steroid (AAS) which is used in the form of esters such as metenolone acetate (brand name Primobolan, Nibal) and metenolone enanthate (brand name Primobolan Depot, Nibal Injection).[2][3][4][5][6] Metenolone esters are used mainly in the treatment of anemia due to bone marrow failure.[7] Metenolone acetate is taken by mouth, while metenolone enanthate is given by injection into muscle.[6]
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| Clinical data | |
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| Trade names | Primobolan, Nibal (as metenolone acetate); Primobolan Depot, Nibal Injection (as metenolone enanthate) |
| Other names | Methenolone; Methylandrostenolone; 1-Methyl-δ1-4,5α-dihydrotestosterone; 1-Methyl-δ1-DHT; 1-Methyl-5α-androst-1-en-17β-ol-3-one |
| AHFS/Drugs.com | International Drug Names |
| Routes of administration | By mouth (as metenolone acetate), intramuscular injection (as metenolone enanthate) |
| Drug class | Androgen; Anabolic steroid |
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| Identifiers | |
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| ECHA InfoCard | 100.005.285 |
| Chemical and physical data | |
| Formula | C20H30O2 |
| Molar mass | 302.458 g·mol−1 |
| 3D model (JSmol) | |
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Side effects of metenolone esters include symptoms of masculinization like acne, increased hair growth, voice changes, and increased sexual desire.[6] Metenolone esters are synthetic androgens and anabolic steroids and hence are agonists of the androgen receptor (AR), the biological target of androgens like testosterone and dihydrotestosterone (DHT).[6][8] They have moderate anabolic effects and weak androgenic effects, as well as no estrogenic effects or risk of liver damage.[6][8] Metenolone esters are androgen esters and prodrugs of metenolone in the body.[6]
Metenolone esters were introduced for medical use in the early 1960s.[6] In addition to their medical use, metenolone esters are used to improve physique and performance.[6] The drugs are controlled substances in many countries and so non-medical use is generally illicit.[6] They have mostly been discontinued for medical use and have limited availability.[5][6]
Medical uses edit
Metenolone, as its esters, is used almost exclusively in the treatment of anemia due to bone marrow failure.[7] It has also been used to treat wasting syndromes due to major surgery, infection, long-term corticosteroid therapy, malnutrition, or other causes.[6] It has also been used to treat osteoporosis and sarcopenia, to inhibit the natural loss of muscle mass with aging, and to promote weight gain in underweight premature infants and children.[6]
Side effects edit
Side effects of metenolone and its esters include virilization among others.[6]
Pharmacology edit
Pharmacodynamics edit
| 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. | |
Due to its double bond between the C1 and C2 positions, metenolone is resistant to metabolism by 3α-hydroxysteroid dehydrogenase (3α-HSD).[6] As such, unlike DHT and the closely related DHT derivatives mestanolone (17α-methyl-DHT) and mesterolone (1α-methyl-DHT), metenolone has considerable anabolic effects.[6]
Pharmacokinetics edit
Metenolone has very low affinity for human serum sex hormone-binding globulin (SHBG), about 16% of that of testosterone and 3% of that of DHT.[9]
Chemistry edit
Metenolone, also known as 1-methyl-4,5α-dihydro-δ1-testosterone (1-methyl-δ1-DHT) or as 1-methyl-5α-androst-1-en-17β-ol-3-one, is a synthetic androstane steroid and derivative of dihydrotestosterone (DHT).[2][3][6] A closely related AAS is mesterolone (1α-methyl-DHT).[2][3][6]
Society and culture edit
Generic names edit
Metenolone is the generic name of the drug and its INN, while methenolone is its BAN.[2][3][4][5] It has also been referred to as methylandrostenolone.[3][5] This synonym should not be confused with methandrostenolone, which is another name for a different AAS known as metandienone.[10]
Doping in sports edit
Metenolone and its esters are banned from use in sports governed by the World Anti-Doping Agency.[11] The NBA and NBPA also banned the use of metenolone and its esters under the Anti-Drug Program. There are known cases of doping in sports with metenolone esters by professional athletes.
References edit
- ^ Anvisa (2023-03-31). "RDC Nº 784 - Listas de Substâncias Entorpecentes, Psicotrópicas, Precursoras e Outras sob Controle Especial" [Collegiate Board Resolution No. 784 - Lists of Narcotic, Psychotropic, Precursor, and Other Substances under Special Control] (in Brazilian Portuguese). Diário Oficial da União (published 2023-04-04). Archived from the original on 2023-08-03. Retrieved 2023-08-15.
- ^ a b c d Elks J (14 November 2014). The Dictionary of Drugs: Chemical Data: Chemical Data, Structures and Bibliographies. Springer. pp. 784–. ISBN 978-1-4757-2085-3.
- ^ a b c d e Index Nominum 2000: International Drug Directory. Taylor & Francis. 2000. pp. 659–660. ISBN 978-3-88763-075-1.
- ^ a b Morton IK, Hall JM (6 December 2012). Concise Dictionary of Pharmacological Agents: Properties and Synonyms. Springer Science & Business Media. pp. 178–. ISBN 978-94-011-4439-1.
- ^ a b c d "List of Androgens and anabolic steroids". Drugs.com.
- ^ a b c d e f g h i j k l m n o p q William Llewellyn (2011). Anabolics. Molecular Nutrition Llc. pp. 625–, 633–. ISBN 978-0-9828280-1-4.
- ^ a b Handelsman DJ (25 February 2015). "Androgen Physiology, Pharmacology, and Abuse". In Jameson JL, De Groot LJ (eds.). Endocrinology: Adult and Pediatric E-Book. Elsevier Health Sciences. pp. 2388–. ISBN 978-0-323-32195-2.
- ^ a b Kicman AT (June 2008). "Pharmacology of anabolic steroids". British Journal of Pharmacology. 154 (3): 502–521. doi:10.1038/bjp.2008.165. PMC 2439524. PMID 18500378.
- ^ Saartok T, Dahlberg E, Gustafsson JA (June 1984). "Relative binding affinity of anabolic-androgenic steroids: comparison of the binding to the androgen receptors in skeletal muscle and in prostate, as well as to sex hormone-binding globulin". Endocrinology. 114 (6): 2100–2106. doi:10.1210/endo-114-6-2100. PMID 6539197.
- ^ Index Nominum 2000: International Drug Directory. Taylor & Francis. 2000. p. 660. ISBN 978-3-88763-075-1.
- ^ "The World Anti-Doping Code: The 2012 Prohibited List" (PDF). World Anti-Doping Agency. Archived from the original (PDF) on 2012-05-13. Retrieved 2012-05-10.