The most common effects of methamphetamine are experienced in the form of a false calm and an increased amount of energy. This leads to the user wanting to challenge the body harder than what is manageable. The result is often that the user's physical and mental well-being falls. Methamphetamine blocks the feeling of hunger, which often cause the user to lose large amounts of weight. In the long term, methamphetamine increases the risk of several diseases and reduces general well-being. Another effect is often that blood pressure increases, which leads to arrhythmia (irregular heartbeat) which in turn increases the risk of a stroke.

Important organs such as the lungs, liver and kidneys also tend to be damaged by continued use of methamphetamine. Brain damage that impairs memory and impairs the user's ability regarding abstract thoughts in the form of, for example, problem solving is also created.