Metenolone acetate

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Metenolone acetate
Clinical data
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
By mouth
Drug classAndrogen; Anabolic steroid; Androgen ester
  • [(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
PubChem CID
CompTox Dashboard (EPA)
ECHA InfoCard100.006.453 Edit this at Wikidata
Chemical and physical data
Molar mass344.495 g·mol−1
3D model (JSmol)
  • 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=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

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]

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]

Side effects[edit]


Androgenic vs. anabolic activity ratio
of androgens/anabolic steroids
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.
Parenteral durations of androgens/anabolic steroids
Medication Form Major brand names Duration
Testosterone Aqueous suspension Andronaq, Sterotate, Virosterone 2–3 days
Testosterone propionate Oil solution Androteston, Perandren, Testoviron 3–4 days
Testosterone phenylpropionate Oil solution Testolent 8 days
Testosterone isobutyrate Aqueous suspension Agovirin Depot, Perandren M 14 days
Mixed testosterone estersa Oil solution Triolandren 10–20 days
Mixed testosterone estersb Oil solution Testosid Depot 14–20 days
Testosterone enanthate Oil solution Delatestryl 14–28 days
Testosterone cypionate Oil solution Depovirin 14–28 days
Mixed testosterone estersc Oil solution Sustanon 250 28 days
Testosterone undecanoate Oil solution Aveed, Nebido 100 days
Testosterone buciclated Aqueous suspension 20 Aet-1, CDB-1781e 90–120 days
Nandrolone phenylpropionate Oil solution Durabolin 10 days
Nandrolone decanoate Oil solution Deca Durabolin 21–28 days
Methandriol Aqueous suspension Notandron, Protandren 8 days
Methandriol bisenanthoyl acetate Oil solution Notandron Depot 16 days
Metenolone acetate Oil solution Primobolan 3 days
Metenolone enanthate Oil solution Primobolan Depot 14 days
Note: All are via i.m. injection. Footnotes: a = TP, TV, and TUe. b = TP and TKL. c = TP, TPP, TiCa, and TD. d = Studied but never marketed. e = Developmental code names. Sources: See template.


Metenolone acetate, or metenolone 17β-acetate, is a synthetic androstane steroid and a derivative of DHT.[1][2][5] It is the C17β acetate ester of metenolone, which itself is 1-methyl-δ1-4,5α-dihydrotestosterone (1-methyl-δ1-DHT) or 1-methyl-5α-androst-1-en-17β-ol-3-one.[1][2][5]

Structural properties of major anabolic steroid esters
Anabolic steroid Structure Ester Relative
mol. weight
AAS contentb
Position Moiety Type Lengtha
Boldenone undecylenate
C17β Undecylenic acid Straight-chain fatty acid 11 1.58 0.63 Long
Drostanolone propionate
C17β Propanoic acid Straight-chain fatty acid 3 1.18 0.84 Short
Metenolone acetate
C17β Ethanoic acid Straight-chain fatty acid 2 1.14 0.88 Short
Metenolone enanthate
C17β Heptanoic acid Straight-chain fatty acid 7 1.37 0.73 Long
Nandrolone decanoate
C17β Decanoic acid Straight-chain fatty acid 10 1.56 0.64 Long
Nandrolone phenylpropionate
C17β Phenylpropanoic acid Aromatic fatty acid – (~6–7) 1.48 0.67 Long
Trenbolone acetate
C17β Ethanoic acid Straight-chain fatty acid 2 1.16 0.87 Short
Trenbolone enanthated
C17β Heptanoic acid Straight-chain fatty acid 7 1.41 0.71 Long
Footnotes: a = Length of ester in carbon atoms for straight-chain fatty acids or approximate length of ester in carbon atoms for aromatic fatty acids. b = Relative androgen/anabolic steroid content by weight (i.e., relative androgenic/anabolic potency). c = Duration by intramuscular or subcutaneous injection in oil solution. d = Never marketed. Sources: See individual articles.


Metenolone acetate was first introduced for medical use in West Germany in 1961 under the brand name Primobolan and in the United States in 1962.[8][5]

Society and culture[edit]

Generic names[edit]

Metenolone acetate is the generic name of the drug and its INNTooltip International Nonproprietary Name, while methenolone acetate is its USANTooltip United States Adopted Name and BANMTooltip British Approved Name.[1][2][3][4][5]

Brand names[edit]

Metenolone acetate is or has been marketed under a number of brand names including Primobolan, Primobolan S, Primonabol, and Nibal.[1][2][3][4][5]


Metenolone acetate is marketed in Japan and Moldova.[4][5]


  1. ^ a b c d e 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.
  2. ^ a b c d e f Index Nominum 2000: International Drug Directory. Taylor & Francis. 2000. pp. 659–661. ISBN 978-3-88763-075-1.
  3. ^ a b c 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.
  4. ^ a b c d e f "List of Androgens and anabolic steroids".
  5. ^ a b c d e f g h i j k l m n o p q r William Llewellyn (2011). Anabolics. Molecular Nutrition Llc. pp. 625–632. ISBN 978-0-9828280-1-4.
  6. ^ 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.
  7. ^ 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.
  8. ^ a b William Andrew Publishing (22 October 2013). Pharmaceutical Manufacturing Encyclopedia (3rd ed.). Elsevier. pp. 2109–. ISBN 978-0-8155-1856-3.