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Metenolone enanthate

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Metenolone enanthate, or methenolone enanthate, sold under the brand names Primobolan Depot and Nibal Injection, is an androgen and anabolic steroid (AAS) medication which is used mainly in the treatment of anemia due to bone marrow failure.[2][3][4][5][6][7] It is given by injection into muscle.[6] Although it was widely used in the past, the drug has mostly been discontinued and hence is now mostly no longer available.[5][6][3] A related drug, metenolone acetate, is taken by mouth.[6]

Metenolone enanthate
Metenolone enanthate.png
Clinical data
Trade namesNibal Injection, Primobolan Depot
Other namesMethenolone enanthate; Metenolone heptanoate; Metenolone 17β-enanthate; NSC-64967; SH-601; SQ-16374; 1-Methyl-4,5α-dihydrotestosterone 17β-heptanoate; 1-Methyl-DHT heptanoate; 1-Methyl-5α-androst-1-en-17β-ol-3-one 17β-heptanoate
Routes of
administration
Intramuscular injection
Drug classAndrogen; Anabolic steroid; Androgen ester
Legal status
Legal status
Pharmacokinetic data
Elimination half-lifeIM: 10.5 days[1]
Identifiers
CAS Number
PubChem CID
ChemSpider
UNII
CompTox Dashboard (EPA)
ECHA InfoCard100.005.584 Edit this at Wikidata
Chemical and physical data
FormulaC27H42O3
Molar mass414.621 g/mol g·mol−1
3D model (JSmol)
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Side effects of metenolone enanthate include symptoms of masculinization like acne, increased hair growth, voice changes, and increased sexual desire.[6] 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).[6][8] It has moderate anabolic effects and weak androgenic effects, as well as no estrogenic effects or risk of liver damage.[6][8] Metenolone enanthate is a metenolone ester and a long-lasting prodrug of metenolone in the body.[6]

Metenolone enanthate was introduced for medical use in 1962.[6] In addition to its medical use, metenolone enanthate is used to improve physique and performance.[6] The drug is a controlled substance in many countries and so non-medical use is generally illicit.[6] It remains marketed for medical use only in a few countries, such as Spain and Turkey.[5][6]

Medical usesEdit

Metenolone enanthate has been studied in the treatment of breast cancer.[9][10]

Side effectsEdit

PharmacologyEdit

PharmacodynamicsEdit

Androgenic vs. anabolic activity
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.

As a derivative of DHT, metenolone, the active form of metenolone enanthate, is not aromatized, and so has no propensity for producing estrogenic side effects like gynecomastia.[6] As an AAS, metenolone enanthate is antigonadotropic and can suppress the hypothalamic–pituitary–gonadal axis and produce reversible hypogonadism and infertility.[6][11]

PharmacokineticsEdit

The biological half-life of metenolone enanthate is reported to be about 10.5 days by intramuscular injection.[1]

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 14–20 days
Testosterone cypionate Oil solution Depovirin 14–20 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 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.

ChemistryEdit

Metenolone enanthate, or metenolone 17β-enanthate, is a synthetic androstane steroid and a derivative of DHT.[2][3][6] It is the C17β enanthate (heptanoate) 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.[2][3][6]

Structural properties of major anabolic steroid esters

Anabolic steroid Structure Ester Relative
mol. weight
Relative
AAS contentb
Durationc
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.

HistoryEdit

Metenolone enanthate was introduced for medical use in 1962 in the United States under the brand name Nibal Depot.[6] It was soon discontinued in the United States and was marketed instead in Europe in the 1960s and 1970s under the brand name Primobolan Depot.[6]

Society and cultureEdit

Generic namesEdit

Methenolone enanthate is the USAN of metenolone enanthate, and methenolone is the BAN of its active form, metenolone.[2][3][4][5] Conversely, metenolone is the INN of metenolone.[2][3][4][5]

Brand namesEdit

Metenolone enanthate is or has been marketed under the brand names Nibal Injection and Primobolan Depot.[2][3][6][5]

AvailabilityEdit

Metenolone enanthate is marketed in Spain and Turkey.[5][6]

Doping in sportsEdit

There are known cases of doping in sports with metenolone enanthate by professional athletes.

ReferencesEdit

  1. ^ a b Pedro Ruiz; Eric C. Strain (2011). Lowinson and Ruiz's Substance Abuse: A Comprehensive Textbook. Lippincott Williams & Wilkins. pp. 358–. ISBN 978-1-60547-277-5.
  2. ^ a b c d e f J. Elks (14 November 2014). The Dictionary of Drugs: Chemical Data: Chemical Data, Structures and Bibliographies. Springer. pp. 784–. ISBN 978-1-4757-2085-3.
  3. ^ a b c d e f g Index Nominum 2000: International Drug Directory. Taylor & Francis. 2000. pp. 659–661. ISBN 978-3-88763-075-1.
  4. ^ a b c I.K. Morton; Judith M. Hall (6 December 2012). Concise Dictionary of Pharmacological Agents: Properties and Synonyms. Springer Science & Business Media. pp. 178–. ISBN 978-94-011-4439-1.
  5. ^ a b c d e f g https://www.drugs.com/international/metenolone.html
  6. ^ a b c d e f g h i j k l m n o p q r s t William Llewellyn (2011). Anabolics. Molecular Nutrition Llc. pp. 633–. ISBN 978-0-9828280-1-4.
  7. ^ J. Larry Jameson; Leslie J. De Groot (25 February 2015). Endocrinology: Adult and Pediatric E-Book. Elsevier Health Sciences. pp. 2388–. ISBN 978-0-323-32195-2.
  8. ^ a b Kicman AT (2008). "Pharmacology of anabolic steroids". Br. J. Pharmacol. 154 (3): 502–21. doi:10.1038/bjp.2008.165. PMC 2439524. PMID 18500378.
  9. ^ Kennedy, B. J.; Yarbro, John W. (1968). "Effect of methenolone enanthate (NSC-64967) in advanced cancer of the breast". Cancer. 21 (2): 197–201. doi:10.1002/1097-0142(196802)21:2<197::AID-CNCR2820210207>3.0.CO;2-R. ISSN 0008-543X.
  10. ^ Notter, G. (1975). "Treatment of Disseminated Carcinoma of the Breast by Metenolone Enanthate". Acta Radiologica: Therapy, Physics, Biology. 14 (6): 545–551. doi:10.3109/02841867509132696. ISSN 0567-8064.
  11. ^ van Breda E, Keizer HA, Kuipers H, Wolffenbuttel BH (Apr 2003). "Androgenic anabolic steroid use and severe hypothalamic-pituitary dysfunction: a case study". Int J Sports Med. 24 (3): 195–196. doi:10.1055/s-2003-39089. PMID 12740738.

External linksEdit