Metenolone

Metenolone
Clinical data
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
ATC code	A14AA04 (WHO) ;
Legal status
Legal status	BR: Class C5 (Anabolic steroids); CA: Schedule IV; US: Schedule III;
Identifiers
	IUPAC name (5S,8R,9S,10S,13S,14S,17S)-17-hydroxy-1,10,13-trimethyl-4,5,6,7,8,9,11,12,14,15,16,17-dodecahydrocyclopenta[a]phenanthren-3-one;
CAS Number	153-00-4 ;
PubChem CID	3037705;
ChemSpider	2301378 ;
UNII	9062ZT8Q5C;
CompTox Dashboard (EPA)	DTXSID10165179 ;
ECHA InfoCard	100.005.285
Chemical and physical data
Formula	C20H30O2
Molar mass	302.458 g·mol−1
3D model (JSmol)	Interactive image;
	SMILES O=C2\C=C(\C)[C@@]3([C@H]1CC[C@@]4([C@@H](O)CC[C@H]4[C@@H]1CC[C@H]3C2)C)C;
	InChI InChI=1S/C20H30O2/c1-12-10-14(21)11-13-4-5-15-16-6-7-18(22)19(16,2)9-8-17(15)20(12,13)3/h10,13,15-18,22H,4-9,11H2,1-3H3/t13-,15-,16-,17-,18-,19-,20-/m0/s1 ; Key:ANJQEDFWRSLVBR-VHUDCFPWSA-N ;

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). Metenolone esters are used mainly in the treatment of anemia due to bone marrow failure. Metenolone acetate is taken by mouth, while metenolone enanthate is given by injection into muscle.

Side effects of metenolone esters include symptoms of masculinization like acne, increased hair growth, voice changes, and increased sexual desire. 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). They have moderate anabolic effects and weak androgenic effects, as well as no estrogenic effects or risk of liver damage. Metenolone esters are androgen esters and prodrugs of metenolone in the body.

Metenolone esters were introduced for medical use in the early 1960s. In addition to their medical use, metenolone esters are used to improve physique and performance. The drugs are controlled substances in many countries and so non-medical use is generally illicit. They have mostly been discontinued for medical use and have limited availability.