Marijuana (Cannabis, Weed): What It Is, Side Effects Risks Marijuana use is associated with an increased risk of injury among adults over 65 Some cannabis marijuana products can be contaminated with microorganisms, pesticides or other harmful substances Some cannabis marijuana products contain amounts of cannabinoids that differ substantially from what’s stated on their labels Cannabis use disorder
Marijuana | History, Effects, THC, Legality | Britannica Marijuana, drug composed of the leaves and flowers of plants in the genus Cannabis Marijuana is known by several other names, including pot, grass, and weed It can vary widely in potency Its active ingredient is tetrahydrocannabinol (THC) Learn more about the history, effects, and legality of marijuana