Metenolone enanthate (or 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.^{[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 respectively. The injection is naturally 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.^{[citation needed]} 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.^{[citation needed]} It is considered one of the safer steroids, meaning it has few side effects.^{[citation needed]} Methenolone has no estrogenic side effects, and its effects on cholesterol levels are minimal.^{[citation needed]} In doses of 200 mg per week or less (intramuscular) blood pressure is rarely altered.^{[citation needed]} It is possibly one of the safer anabolic steroids for females due to very low virilization effects in short-term usage.^{[citation needed]} Methenolone is also not overly suppressive of the hypothalamic-pituitary-gonadal axis, although how suppressive is debatable.^{[citation needed]} For this reason, many bodybuilders use it in between steroid cycles during their "off-time" to help maintain their gains and strength. The long term safety of such a practice is possibly dangerous and can lead to permanent suppression of the HPTA.^[1]