Marijuana is an herb that grows in many places around the world. It is also called hemp, reefer, or cannabis. Its scientific name is Cannabis sativa. Historically, it has had many uses in different cultures. These including reducing pain and increasing appetite.
Marijuana contains chemicals called cannabinoids.
Marijuana was legal for medical use in the United States until the late 1930s. These led lawmakers to believe that marijuana caused crime, violence, insanity, and death. In 1970, US drug law classified marijuana as having a high potential for abuse and no medical use. Marijuana was later found to have other health benefits. It can lower pressure within the eye.