Cannabis is a genus of plants that has been used for recreational and entheogenic purposes, as well as in traditional medicine, for centuries. The psychoactive drug extracted from the plant, known as marijuana, has a wide range of health effects that vary by user. It can affect a person’s sense of reality (for example, colors may seem brighter) and make them feel euphoric or disoriented. It can also cause anxiety and paranoia. In rare cases, it can lead to a short-term psychosis with hallucinations or even suicidal thoughts. In addition, it can impair thinking, memory, and learning functions. It is also thought to influence how the brain develops in teens who use it regularly. Fatalities due to cannabis use are rare.

When a person smokes marijuana, THC is carried from the lungs into the bloodstream and reaches brain areas involved in memory, thinking, concentration, movement, coordination, sensory and time perception, and pleasure. THC acts on specific brain cell receptors that ordinarily react to natural cannabinoid neurotransmitters.

The Food and Drug Administration (FDA) has approved a medication derived from cannabis, called Epidiolex, to treat two severe forms of epilepsy in children. It has also approved dronabinol (brand names Marinol and Syndros) and nabilone (Cesamet) to treat nausea caused by cancer chemotherapy and to increase appetite in people with AIDS who don’t want to eat (wasting syndrome). FDA is continuing to monitor the market and take action to protect consumers from products that claim to have therapeutic benefits for which they are not approved.