This medication is used in men who do not make enough of a natural substance called testosterone. In males, testosterone is responsible for many normal functions, including growth and development of the genitals, muscles, and bones. It also helps cause normal sexualdevelopment (puberty) in boys. Fluoxymesterone is similar to the natural testosterone produced by your body. It belongs to a class of drugs known as androgens. It works by affecting many body systems so that the body can develop and function normally.Fluoxymesterone may also be used in certain adolescent boys to cause puberty in those with delayed puberty.

Take this medication by mouth with or without food, usually 1 to 4 times a day, as directed by your doctor.Dosage is based on your medical condition, testosterone blood levels, and response to treatment.Use this medication regularly in order to get the most benefit from it. To help you remember, take it at the same times each day.Do not suddenly stop using fluoxymesterone if you have been using it regularly for an extended time or if it has been used in high doses. In such cases, your body will no longer make its own testosterone, and withdrawal reactions (such as tiredness, weakness, depression) may occur. To prevent withdrawal reactions, your doctor may reduce your dose gradually. Consult your doctor or pharmacist for more details, and report any withdrawal reactions immediately.Abnormal drug-seeking behavior is possible with this medication, and it is frequently misused for its muscle-enhancing effects. Do not increase your dose, take it more frequently, or take it for a longer time than prescribed. Doing so may increase serious side effects (such as increased risk for heart disease, stroke, liver disease, ruptured tendons/ligaments, improper bone development in adolescents). Properly stop the medication when so directed.Tell your doctor if your condition does not improve or worsens.