Who used steroids?
A lot of people have used steroids. Most of these people do so for medical reasons, but some of them were famous, too. Many of these are known for having major careers in professional sport and competition, such as baseball, football (of all kinds), and basketball. A lot of Olympians have been disqualified after the fact for having used steroids, amongst other banned substances.
If used properly, steroids can help the body heal from inflammation - they are very good for conditions such as arthritis and asthma, which are aggravated by swelling. If used improperly, such as in an attempt to "bulk up," steroids can cause irreversible damage to the body, because in illegal use a proper dose is not used. Using too many steroids does damage the body.