Bolasterone Trade names Myagen, Methosarb Other names U-19763; NSC-66233; 7α,17α-Dimethyltestosterone; 7α,17α-Dimethylandrost-4-en-17β-ol-3-one, Piratestosterone. Routes of administration By mouth Legal status
BR : Class C5 (Anabolic steroids)[ 1]
(7R ,8R ,9S ,10R ,13S ,14S ,17S )-17-hydroxy-7,10,13,17-tetramethyl-2,6,7,8,9,11,12,14,15,16-decahydro-1H -cyclopenta[a ]phenanthren-3-one
CAS Number PubChem CID ChemSpider UNII ChEMBL CompTox Dashboard (EPA ) ECHA InfoCard 100.015.018 Formula C 21 H 32 O 2 Molar mass 316.485 g·mol−1 3D model (JSmol)
O=C4\C=C3/[C@]([C@H]2CC[C@]1([C@@H](CC[C@@]1(O)C)[C@@H]2[C@H](C)C3)C)(C)CC4
InChI=1S/C21H32O2/c1-13-11-14-12-15(22)5-8-19(14,2)16-6-9-20(3)17(18(13)16)7-10-21(20,4)23/h12-13,16-18,23H,5-11H2,1-4H3/t13-,16+,17+,18-,19+,20+,21+/m1/s1
Key:IVFYLRMMHVYGJH-VLOLGRDOSA-N
Bolasterone (INN Tooltip International Nonproprietary Name , USAN Tooltip United States Adopted Name ) (brand names Myagen , Methosarb ; former developmental code name U-19763 ), also known as 7α,17α-dimethyltestosterone , is a 17α-alkylated androgen/anabolic steroid (AAS) which is used in veterinary medicine.[ 2] [ 3] It has close structural similarity to testosterone , and like methyltestosterone has a methyl group at C17α in order to increase oral bioavailability.[ 2] In addition, it is also 7α-methylated, similar to its 7β-methylated isomer calusterone .[ 2] The medication has a low to moderate ratio of anabolic to androgenic activity, similar to that of fluoxymesterone .[ 4]
Bolasterone is on the World Anti-Doping Agency's list of prohibited substances,[ 5] and is therefore banned from use in most major sports.
Chemistry
Synthesis
The chemical synthesis was reported:[ 6] Patent:[ 7]
The oxidation of methyltestosterone [58-18-4] (1 ) with chloranil gives 17alpha-methyl-6,7-dehydrotestosterone [5585-85-3] (2 ). The conjugate addition of methylmagnesium bromide in the presence of a catalytic amount of cuprous iodide (c.f. Gilman reagent) gives a mixture of bolasterone and calusterone , with the former predominating.
See also
Mibolerone (19-normethyl-bolasterone)
References
^ 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 Elks J (14 November 2014). The Dictionary of Drugs: Chemical Data: Chemical Data, Structures and Bibliographies . Springer. pp. 646–. ISBN 978-1-4757-2085-3 .
^ Morton IK, Hall JS (6 December 2012). Concise Dictionary of Pharmacological Agents: Properties and Synonyms . Springer Science & Business Media. pp. 52–. ISBN 978-94-011-4439-1 .
^ Kochakian CD (6 December 2012). Anabolic-Androgenic Steroids . Springer Science & Business Media. pp. 377, 401. ISBN 978-3-642-66353-6 .
^ "The World Anti-Doping Code: The 2020 Prohibited List" (PDF) . World Anti-Doping Agency. Retrieved 2019-12-28 .
^ Campbell, J. A.; Babcock, J. C. (August 1959). "The Synthesis of Some 7α- and 7β-Methyl Steroid Hormones 1" . Journal of the American Chemical Society . 81 (15): 4069– 4074. doi:10.1021/ja01524a063 . Retrieved 29 January 2026 .
^ U.S. patent 3,341,557 Babcock, J. C.; Campbell, J. A.; Upjohn Co (1967).
Androgens and antiandrogens
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# WHO-EM
‡ Withdrawn from market
Clinical trials:
† Phase III
§ Never to phase III
See also
Androgen receptor modulators
Estrogens and antiestrogens
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List of androgens/anabolic steroids
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Nonsteroidal: 198RL26
ACP-105
AC-262,536
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Andarine (acetamidoxolutamide, androxolutamide, GTx-007, S-4)
BMS-564,929
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ORM-11984
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See also
Receptor/signaling modulators
Androgens and antiandrogens
Estrogen receptor modulators
Progesterone receptor modulators
List of androgens and anabolic steroids