Crystal methamphetamine is a colorless, odorless form of d-methamphetamine, a powerful and highly addictive synthetic (man-made) stimulant. Crystal methamphetamine typically resembles small fragments of glass or shiny blue-white "rocks" of various sizes. Like powdered methamphetamine (another form of d-methamphetamine), crystal methamphetamine is abused because of the long-lasting euphoric effects it produces. Crystal methamphetamine, however, typically has a higher purity level and may produce even longer-lasting and more intense physiological effects than the powdered form of the drug.

Crystal methamphetamine typically is smoked using glass pipes similar to pipes used to smoke crack cocaine. Crystal methamphetamine also may be injected. A user who smokes or injects the drug immediately experiences an intense sensation followed by a high that may last 12 hours or more.

Crystal methamphetamine is used by individuals of all ages and is increasingly gaining in popularity as a club drug. It is difficult to determine how many individuals in the United States use crystal methamphetamine because most illicit drug use surveys do not distinguish between crystal methamphetamine and powdered methamphetamine. Those surveys that do draw such a distinction reveal that use of crystal methamphetamine is prevalent. According to the University of Michigan's Monitoring the Future Survey, nearly 5 percent of high school seniors in the United States used crystal methamphetamine at least once in their lifetime and 3 percent used the drug in the past year.

Crystal methamphetamine use is associated with numerous serious physical problems. The drug can cause rapid heart rate, increased blood pressure, and damage to the small blood vessels in the brain--which can lead to stroke. Chronic use of the drug can result in inflammation of the heart lining. Overdoses can cause hyperthermia (elevated body temperature), convulsions, and death.

Individuals who use crystal methamphetamine also may have episodes of violent behavior, paranoia, anxiety, confusion, and insomnia. The drug can produce psychotic symptoms that persist for months or years after an individual has stopped using the drug.

Crystal methamphetamine users who inject the drug expose themselves to additional risks, including contracting HIV (human immunodeficiency virus), hepatitis B and C, and other blood-borne viruses. Chronic users who inject methamphetamine also risk scarred or collapsed veins, infections of the heart lining and valves, abscesses, pneumonia, tuberculosis, and liver or kidney disease.