Methamphetamine is a potent central nervous system stimulant that is mainly used as a recreational drug and less commonly as a second-line treatment for attention deficit hyperactivity disorder and obesity.
A user can become addicted quickly and soon finds they will do anything to have the rush again. As they continue to use the drug, they build up a tolerance. That means they need higher doses to get the same high. The higher the dose, the higher the risks.