Metenolone acetate

Metenolone acetate, or methenolone acetate, sold under the brand names Primobolan and Nibal, is an androgen and anabolic steroid (AAS) medication which is used mainly in the treatment of anemia due to bone marrow failure.^{[1][2][3][4][5][6]} It is taken by mouth.^[5] Although it was widely used in the past, the drug has mostly been discontinued and hence is now mostly no longer available.^[4][5][2] A related drug, metenolone enanthate, is given by injection into muscle.^[5]

Trade namesPrimobolan, Primobolan S, Primonabol, Nibal

Other namesMethenolone acetate; NSC-74226; SH-567; SQ-16496; Methenolone 17β-acetate; 1-Methyl-δ¹-4,5α-dihydrotestosterone 17β-acetate; 1-Methyl-δ¹-DHT acetate; 1-Methylandrost-1,4-dien-17β-ol-3-one 17β-acetate

Routes of
administrationBy mouth

Drug classAndrogen; Anabolic steroid; Androgen ester

Quick facts Clinical data, Trade names ...

Metenolone acetate

Clinical data
Trade names	Primobolan, Primobolan S, Primonabol, Nibal
Other names	Methenolone acetate; NSC-74226; SH-567; SQ-16496; Methenolone 17β-acetate; 1-Methyl-δ1-4,5α-dihydrotestosterone 17β-acetate; 1-Methyl-δ1-DHT acetate; 1-Methylandrost-1,4-dien-17β-ol-3-one 17β-acetate
Routes of administration	By mouth
Drug class	Androgen; Anabolic steroid; Androgen ester
Identifiers
IUPAC name [(5S,8R,9S,10S,13S,14S,17S)-1,10,13-Trimethyl-3-oxo-4,5,6,7,8,9,11,12,14,15,16,17-dodecahydrocyclopenta[a]phenanthren-17-yl] acetate
CAS Number	434-05-9
PubChem CID	252372
ChemSpider	221129
UNII	W75590VPKQ
CompTox Dashboard (EPA)	DTXSID40963004
ECHA InfoCard	100.006.453
Chemical and physical data
Formula	C22H32O3
Molar mass	344.495 g·mol−1
3D model (JSmol)	Interactive image
SMILES CC1=CC(=O)C[C@H]2[C@]1([C@H]3CC[C@]4([C@H]([C@@H]3CC2)CC[C@@H]4OC(=O)C)C)C
InChI InChI=1S/C22H32O3/c1-13-11-16(24)12-15-5-6-17-18-7-8-20(25-14(2)23)21(18,3)10-9-19(17)22(13,15)4/h11,15,17-20H,5-10,12H2,1-4H3/t15-,17-,18-,19-,20-,21-,22-/m0/s1 Key:PGAUJQOPTMSERF-QWQRBHLCSA-N

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Side effects of metenolone acetate include symptoms of masculinization like acne, increased hair growth, voice changes, and increased sexual desire.^[5] 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).^[5][7] It has moderate anabolic effects and weak androgenic effects, as well as no estrogenic effects or risk of liver damage.^[5][7] Metenolone enanthate is a metenolone ester and a prodrug of metenolone in the body.^[5]

Metenolone acetate was introduced for medical use in 1961.^[8][5] In addition to its medical use, metenolone acetate is used to improve physique and performance.^[5] The drug is a controlled substance in many countries and so non-medical use is generally illicit.^[5] It remains marketed for medical use only in a few countries, such as Japan and Moldova.^[4][5]