Fluoxymesteron is an extremely powerful synthetic metabolic androgen steroid, released by Upjohn for the first time by trade name Halotestin in the late 1950s. Soon after, Ciba Pharmaceuticals will release hormones under the Ultandren name, but Halotestin is still the most well-known brand. Pharmacia, formerly known as Upjohn, now manufactures Halotestin brand names.