Product name: Primobolan
Chemical Structure: 17beta-Hydroxy-1-methyl-5alpha-androst-1-en-3-one
Metenolone enanthate (methenolone enanthate) is a dihydrotestosterone (DHT) based anabolic steroid. It is an ester derivative of methenolone sold commonly under the brand names Primobolan (tablet form) or Primobolan Depot (injectable). When it interacts with the aromatase enzyme it does not form any estrogens.[medical citation needed] It is used by people who are very susceptible to estrogenic side effects, having lower estrogenic properties than nandrolone. Methenolone, in form of enanthate and acetate, is available as an injection or as an oral formulation. The injection is regarded as having a higher bioavailability. It is an enanthate ester which is quite long-acting. Because it by-passes hepatic breakdown on the first pass, it also has a higher survival rate. The tablets are in a short-lived acetate form. Methenolone is not 17-alpha-alkylated, but 1-methylated for oral bioavailability. This reduces the stress on the liver, but also the availability. In doses of 200 mg per week or less (intramuscular) blood pressure is rarely altered.
Methenolone can be suppressive of the hypothalamic-pituitary-gonadal axis.