Steroid hormones related to the male sex hormone testosterone. They promote the development of masculine characteristics and increase muscle growth. Anabolic steroids have been used medically for various conditions but are also used illegally by sportsmen and women and by bodybuilders. They have a number of deleterious side effects and are a controlled drug in the UK and many other countries. Their use is banned by nearly all major sports regulating bodies. They can be detected in blood and urine by gas chromatography-mass spectroscopy.