Oxymetholone (also known as anapolon or anadrol) is a very drastic synthetic steroid, 17-alpha-alkylated modification of dihydrotestosterone. Oxymetholone was developed in the 1960s to treat severe anemia and muscle wasting diseases and as such is generally a high quality anabolic steroid for providing massive gains in weight in performance enhancing athletes.
Oxymetholone is a derivative of dihydrotestosterone, which gives it a chemical structure that does not aromatize. Despite the fact that oxymetholone does not directly convert to estradiol, it itself has pronounced estrogenic properties. It should be remembered that because of this peculiarity only antiestrogens would be able to combat with estrogenic side effects, but not aromatase inhibitors, because aromatase is not involved into the process.
Some suggest that oxymetholone`s estrogenic activity relates to the progestogenic one, like with nandrolones. Side effects may be similar. However, medical studies have shown that oxymetholone does not possess any progestogenic activity.