Testosterone not only brings out male sexual traits, it also causes muscles to grow.
Some people take anabolic steroid pills or injections to try to build muscle faster.
But these steroids also have other effects. They can cause changes in the brain and body that increase risks for illness and they may affect moods. You may have heard that some athletes use anabolic steroids to gain size and strength. Maybe you've even seen an anabolic steroid user develop bigger muscles over time. But while anabolic steroids can make some people look stronger on the outside, they may create weaknesses on the inside.