Anabolic steroids are are a class of steroid hormones that resemble the chemical structure of the body's naturally made sex hormone, testosterone. Testosterone directs the body to produce or enhance male characteristics such as increased muscle mass, facial hair growth, and deepening of the voice. Testosterone is an important part of male development during puberty. When anabolic steroids increase the levels of testosterone in the blood, they stimulate muscle tissue in the body to grow larger and stronger (anabolism). As a result, they are sold as drugs to increase muscle mass, and sometimes used illegally by athletes to improve performance. However, the effects of too much testosterone circulating in the body can be harmful over time. 
Use of Steroids
Anabolic androgenic steroids are synthetic derivatives of the male hormone testosterone. They are taken to build muscle, enhance performance, and improve appearance. The majority of steroid users tend to be young, male athletes. Athletes in endurance sports such as swimming, running, and cycling also use steroids. The drug has “muscle-building” effects that help the body retain protein, a necessary building block for the growth of muscles. They are used to quicken puberty and maturation and some male and female models take them to improve their body image. Physically demanding occupations, like law enforcement, bouncers, or military personnel may use steroids to build strength. 
Surveys of students in eighth, tenth, and twelfth grade, show that 1.7% of eighth graders, 2.0% of tenth graders, and 2.6% of twelfth graders reported using steroids at least once in their lifetimes. The Centers for Disease Control and Prevention (CDC) also conducted a survey of high school students throughout the United States in 2005, the Youth Risk Behavior Surveillance System (YRBSS) 4.8% of all high school students have used steroid pills/shots without a doctor's prescription. 
How they are taken
Steroids can either be taken orally in a tablet form or injected intramuscularly. Users rely on other sources and gossip to determine their dosage levels. Individuals abusing steroids take mega doses of hundreds of milligrams per day. However, doctors prescribe only 1 to 5 mg. per day for legitimate medical uses. Users typically take many types of steroids in combination with other drugs to get better results. This is known as “stacking.” Users often take steroids in “cycles.” They will use steroids for six to twelve weeks at a time and then take a break from them. Steroid users do this to avoid building up a tolerance. 
Currently, there are more than 100 different types of anabolic steroids that have been developed, and each requires a prescription to be used legally in the United States.  Some common names of anabolic androgenic steroids include Anatrofin, Anaxvar, Annadrol, Bolasterone, Decadiabolin, Decadurabolin, Dehydropiandrosterone (DHEA), Delatestryl, Dianiabol, Dihydrolone, Durabolin, Dymethazine, Enoltestovis, Equipose, Gamma Hydroxybutilate, Maxibolin, Methatriol, Methyltestosterone, Parabolin, Primobolin, Quinolone, Therabolin, Trophobolene, and Winstrol. 
Slang terms include Gym Candy, Pumpers, Stackers, A’s, Anabolics, Arnolds, Bolins, GHB, Oxys, Anabols, Balls or Bulls, Delatestryl, Maxibolin, Weight Trainers, Arnies, Dep-testosterone, Methyltestosterone, Rhoids, and Juice. 
There are various symptoms to look out for if someone you know is abusing steroids. Some of them include: rapid weight gain and muscle development, acne flare up, fluid retention, jaundice yellow tinge to eyes and skin, mood swings and depressed moods, aggressive behavior, and premature balding.
Unfortunately, steroid abusers risk a variety of unwanted side effects. The androgenic effects cause the development of a deep voice, facial and body hair, muscle mass, acne and breast development in men.  Anabolic steroid abuse is associated with side effects that are physically unattractive and life threatening. If the abuser stops taking the drug most of the effects are reversible; but some can be permanent. In addition to the physical effects, anabolic steroids can also cause increased irritability and aggression. 
The incidence of life-threatening effects appears to be low, but serious effects may be under-recognized or under-reported. Steroid abuse has been associated with cardiovascular diseases (CVD), including heart attacks and strokes, in some athletes younger than 30. Steroids contribute to this development partly by changing the levels of lipoproteins that carry cholesterol in the blood. Steroids increase the level of low-density lipoprotein (LDL) and decrease the level of high-density lipoprotein (HDL). High LDL and low HDL levels increase the risk of atherosclerosis, which is a condition where fatty substances are deposited inside arteries and disrupt blood flow. The result of a heart attack can occur if blood is prevented from the heart. If it is not reaching the brain, the result can be a stroke. Steroids can also increase the risk of blood clots that will form in blood vessels. This potentially disrupts the blood flow and damages the heart muscle so that it does not pump blood to the body effectively. Also, another significant danger includes HIV infection if needles are shared.
- Steroids:Just the Facts Texas Commission on Alcohol and Drug Abuse
- Steroids U.S. Drug Enforcement Administration
- Steroids Kids Health