Steroids: Drug Facts by Office of National Drug Control Policy
Anabolic steroids can be taken orally, injected intramuscularly, or rubbed on the skin when in the form of gels or creams. These drugs are often used in patterns called cycling. This involves taking multiple doses of steroids over a specific period of time, stopping for a period, and starting again. Anabolic steroid abuse has been associated with a wide range of adverse side effects ranging from some that are physically unattractive, such as acne and breast development in men, to others that are life threatening.
http://www.whitehousedrugpolicy.gov/drugfact/steroids/index.html