Bodybuilding Pose

Performance enhancing substances
Some bodybuilders use drugs such as anabolic steroids and precursor substances such as prohormones to increase muscle hypertrophy. Most of the substances require medical prescriptions to be accessed legally. Anabolic steroids cause muscle hypertrophy of both types (I and II) of muscle fibers caused likely by an increased synthesis of muscle proteins and are accompanied with undesired side effects including hepatotoxicity, gynecomastia, acne, male pattern baldness and a decline in the body's own testosterone production, which can cause testicular atrophy. Other controlled substances used by competitive bodybuilders include human growth hormone (HGH), which can cause acromegaly.