The effects of steroids will vary from person to person depending on the following characteristics:
- Physical size.
- Gender.
- Diet.
- Exercise level.
- Age.
- Health.
- The amount of steroid used and its purity.
- Whether the steroid is taken orally or by injection.
Risks are especially high for young people. If steroids are taken while a person is still growing they can cause a number of problems including stunted growth.
Unsafe injecting practices also carry the risk of transmission of HIV and other bloodborne diseases such as hepatitis B and hepatitis C. Injecting can cause muscle damage, scarring and infection at the injection site.
Using steroids may cause many negative physical and psychological (mental) side effects. Some of the effects are irreversible and some can lead to death. While the side effects of steroid use is reversible in men this is not the case for women for whom the side-effects are more likely to be permanent.
Many steroids are illegally made and can contain harmful, unknown substances that may increase the side effects. Often black market steroids are designed for animals and some may not contain any anabolic steroids at all.