Methamphetamines are an addictive stimulant that is both long-lasting and toxic to the brain. They are chemically similar to speed (amphetamine) but have far more dangerous effects on the body’s central nervous system. Methamphetamine is a white, odorless crystalline powder that easily dissolves in water or alcohol. Users may call it meth, ice, crank, chalk, crystal, fire, glass, go fast, speed, tina, or T. Methamphetamine, even in small doses, can increase wakefulness and physical activity and decrease appetite. Long-term methamphetamine abuse results in many damaging effects, including addiction. Chronic methamphetamine users exhibit symptoms that can include violent behavior, anxiety, confusion, and insomnia. Methamphetamine can produce a rapid heart rate, irregular heartbeat, increased blood pressure, and elevated body temperatures. These symptoms, especially at high doses, can cause death from stroke, heart attack, or organ failure due to overheating. In addition, methamphetamine works by changing the way the brain functions, leading to impaired verbal skills and reduced motor function.