Speed is the popular name for methamphetamine (also called methedrine), a drug that has strong stimulant effects on the central nervous system (the brain and spinal cord). Speed is similar to amphetamine, but it has greater effects on the central nervous system and lesser effects on the cardiovascular and gastrointestinal systems. In other words, like amphetamine, speed causes increased activity, increased talkativeness, more energy and less fatigue, decreased food intake, and a general sense of well-being. Because speed dissolves more easily in water than amphetamine, drug abusers generally choose to inject speed. Injecting the drug into the veins results in the production of a rush. Some users describe the rush as the most desirable effect of the drug.

A razor blade is used to cut speed into lines for snorting. Methamphetamines stimulate the central nervous system and suppress appetite. Prolonged use can lead to addiction and psychotic mental...