Side-effects from the use of steroids are extremely common and can be quite significant. Most side-effects are reversible once the athlete stops usage although serious long-term side-effects and even death have occurred as a direct result of steroid use.
• Decreased sperm production and sex drive
• Increased aggression, irritability and mood swings
• Liver disorders
• Baldness (alopecia)
• Hypertension (high blood pressure)
• Raised cholesterol
• Gynecomastia (development of over-sized mammary glands in males)
• Menstrual irregularities (in women)
• Hirsuitism (excessive hair growth occurring in females which follows the pattern of male hair growth, . facial)
• Deepening of the voice
• Reduced immunity
• Possible development of tumors (wilm’s tumor, prostate carcinoma and leukemia have been reported, although a connection is not proven)
The gains made by athletes in uncontrolled observations have been much more impressive. Weight gains of thirty or forty pounds, coupled with thirty percent increases in strength, are not unusual. Such case studies lack credibility because of the absence of scientific controls. However, it would be foolish to completely disregard such observations because the "subjects" have been highly trained and motivated see the articles on pharmacology of sport and sports medicine in the countries of the former Soviet Union for more information on anabolic steroids.