Marijuana is made from the dried leaves and buds of the Cannabis sativa plant. While the Food and Drug Administration (FDA) hasn’t recognized or approved the use of the marijuana plant as medicine, many states have legalized marijuana for medical use.

Marijuana is a controlled substance in the U.S. Federal law prohibits its use for any reason. Many states, however, allow medical use of marijuana to treat pain, nausea and other symptoms.By Mayo Clinic Staff

Medical marijuana — also called medical cannabis — is a term for derivatives of the Cannabis sativa plant that are used to relieve serious and chronic symptoms.

Cannabis sativa contains many active compounds, but two are of interest for medical purposes: THC (delta-9 tetrahydrocannabinol) and CBD (cannabidiol). THC is the primary ingredient in marijuana that makes people “high.”

Is medical marijuana legal in the U.S.?

U.S. federal law prohibits the use of whole plant Cannabis sativa or its derivatives for any purpose. CBD derived from the hemp plant (< 0.3% THC) is legal under federal law to consume.

Many states allow THC use for medical purposes. Federal law regulating marijuana supersedes state laws. Because of this, people may still be arrested and charged with possession in states where marijuana for medical use is legal.

The FDA has approved two drugs, dronabinol (Marinol, Syndros) and nabilone (Cesamet), made from synthetic forms of ingredients found in marijuana. They can be legally prescribed for the treatment of nausea and vomiting caused by chemotherapy when other treatments have failed. Dronabinol might also be used for the treatment of anorexia associated with weight loss in people with AIDS.

Medical marijuana is available as an oil, pill, vaporized liquid and nasal spray, as dried leaves and buds, and as the plant itself. The herb is typically used to treat chronic pain, nausea and vomiting associated with cancer treatment and muscle spasms.

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