Methamphetamine was first synthesized in 1887 in Germany and was later used medically to treat various conditions. More potent forms were later discovered, including one used by Japanese military during World War II to keep soldiers alert. In the 1950s, legal methamphetamine tablets were produced and misused. By the 1960s, injectable meth became widely abused. While production of injectable meth was restricted in the 1970s, it continued to be made illegally. Methamphetamine is classified as a psychoactive stimulant that can have serious physical and health risks with addiction being very difficult to treat.