Doctors can prescribe steroids to patients for legitimate medical purposes, such as loss of testicular function, breast cancer, low red blood cell count, delayed puberty, and weakened states as a result of surgery or illness. Veterinarians administer steroids to animals (e.g., cats, cows, dogs, and horses) for legitimate purposes, such as promoting feeding efficiency and improving weight gain, vigor, and coat. They are also used in veterinary practice to treat anaemia and counteract tissue degradation during illness and trauma. For purposes of illegal use there are several sources; the most common illegal source is the smuggling of steroids into the United States from other countries such as Mexico and European countries.
Smuggling from these areas is easier because no prescription is required to purchase steroids. Less commonly, steroids found on the illicit market are diverted from legitimate sources (for example, theft or inappropriate prescriptions) or produced in clandestine laboratories. Anabolic steroids can be used as performance-enhancing drugs that increase muscle mass and decrease fat, as well as causing many undesirable effects. Some athletes, weightlifters, and bodybuilders take them regularly to improve their physical performance and strengthen their bodies.
There are up to 32 types of anabolic steroids listed on commercial websites. Some have only medicinal uses, such as Nebido. Anadrol is an example of a steroid with both medicinal and performance uses. Many people who inject anabolic steroids may use non-sterile injection techniques or share contaminated needles with other users.
This puts these steroid users at risk for life-threatening viral infections, such as HIV and hepatitis B and C. 76 In addition, animal models indicate that anabolic steroids suppress the immune system77, which could worsen infections.