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. 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.
Use by Major League Baseball players
In February 2009, Sports Illustrated reported that Alex Rodriguez tested positive for two anabolic steroids, testosterone and metenolone enanthate, while playing for the Texas Rangers in 2003. He claims to have purchased them over the counter, in the Dominican Republic. However, “boli,” as he referred to it, is an illegal substance in the Dominican Republic. In an interview with ESPN two days after the SI revelations, Rodriguez admitted to using banned substances from 2001 to 2003, citing “an enormous amount of pressure to perform,” but said he had not since then used banned performance-enhancing substances. He said he did not know the name(s) of the particular substance(s) he was using, and would not specify whether he took them in injectable form.
Methenolone enanthate, which has no approved prescriptive use in the United States of America, is the same steroid to which Barry Bonds allegedly tested positive in 2000 and 2001. A weak steroid on its own, it is generally used in conjunction with other steroids. The drug is generally preferred in injected rather than oral form due to its cost.