Fluoxymesterone is structurally close to another fairly strong androgen – Methyltestosterone. It was obtained by modifying testosterone in the following three positions: this is the 9-fluoro group, 11-beta-hydroxy group and 17-alpha-methyl group. The first of these modifications determines the name of this drug and is mainly aimed at increasing its androgenic activity.
The second improvement of Fluoxymesterone, which is responsible to some extent for the effect, prevents the conversion of AAS to estrogens in the body. And the third one allows to extend the half-life period in the form for peroral administration and protects the drug from destruction when passing through the liver, while maintaining the concentration of the active substance in the blood as much as possible.
Initially, this steroid was produced exclusively for medical use. It was used as an androgenic means in the treatment of delayed sexual development in men and male hypogonadism, as well as in breast cancer in women. For today, medical practice has actually completely abandoned the use of drugs based on this AAS. But, in sports, their popularity is only growing. Halotestin is quite often used in preparation for competitions due to the specifics of its action. It is considered one of the best steroid remedies for an emergency increase in strength and, as a result, sports performance.