The science of steroids – and how cheaters are caught
Take a look at the chemistry behind the performance-enhancing drugs – and ways scientists sniff them out.
Steroids have legitimate medical uses, such as treating growth disorders and cancer, but many people associate them with drug cheats in sport.
A type of steroid, called anabolic-androgenic steroids, encourages the body to make more and strengthen muscle. But there are also loads of bad side-effects such as kidney and liver problems and the old "roid rage".
So how are steroid abusers caught? The American Chemical Society's Reactions team explains the intircate science in the video below.