Fluoxymesterone (also known as Halotestin) is an orally effective anabolic steroid with very strong androgenic activity, derived from methyltestosterone, that was first launched on the market by the American pharmaceutical company Upjohn in 1957 under the brand name "Halotestin." The clinical purpose of fluoxymesterone originally consisted of the treatment of male hypogenitalism, delayed puberty in men, and breast neoplasms in women. This potent, orally active, non-aromatizable steroid exhibits extremely strong androgenic properties. This makes fluoxymesterone a great strength drug, and the predominant effects seen when using it are increased strength, increased muscle density, and definition. 

Fluoxymesterone is an orally available C17-alpha-alkylated anabolic steroid with a very strong androgenic effect. More specifically, it is a methyltestosterone derivative, differing by the addition of 11-beta-hydroxy and 9-alpha-fluoro groups. An intriguing aspect of Halotestin use is significantly increased erythropoiesis (the production of red blood cells) and enhanced branching of the capillary network in muscles, which, as a result of improved blood supply, greatly increases strength and endurance. Fluoxymesterone is a very potent androgen that does not aromatize and does not convert to estradiol. 

WARNING: Due to its C17-alpha-alkylation fluoxymesterone may exert high stress on the liver. Therefore, healthy lifestyle choices and the use of supplements to promote liver health are advisable. When using fluoxymesterone, special attention should be paid to the liver by regularly checking the status of liver enzymes. For this reason, the recommended Halotestin cycle duration should be no more than 6 weeks.