Medical marijuana, or medical cannabis, uses the cannabis plant or chemicals in it to treat symptoms or conditions. Medical marijuana mostly comes in the same forms as recreational marijuana, but there also are highly purified and lab-made versions used for certain conditions.The cannabis plant contains more than 100 different chemicals called cannabinoids. Each one has a different effect on the body. Delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) are the main chemicals used in medicine. THC also produces the “high” people feel when they smoke marijuana or eat foods containing it.
As of 2023, a broad range of medical marijuana products were legal in 38 states, three territories, and the District of Columbia but remained illegal under federal law.
States where medical marijuana is legal have approved it for a varying list of conditions. Depending on where you live, these might include:
Severe and chronic pain
Multiple sclerosis and muscle spasms
Severe nausea and vomiting caused by cancer treatment
Epilepsy and seizures
Alzheimer’s disease
Amyotrophic lateral sclerosis (ALS)
HIV/AIDS
Crohn’s disease
Glaucoma
Migraine
Anorexia
Extreme weight loss and weakness (wasting syndrome)
Irritable bowel syndrome
Post-traumatic stress disorder
It is important to know that many of the uses that states allow aren’t backed by strong scientific evidence. This is partly because researchers find it hard to do studies on a drug that remains illegal under federal law, even when it’s allowed by states.
It’s also important to realize that cannabis is almost always used to treat symptoms — like the muscle spasms of multiple sclerosis and the loss of appetite caused by HIV drugs — rather than the conditions themselves.
Medical Marijuana: What Does It Treat?
More and more states are legalizing marijuana to treat pain and illness. Find out what conditions it’s used for and the known side effects.
Benefits of Medical Marijuana
Cannabinoids, the active chemicals in medical marijuana, are similar to chemicals the body makes that are involved in appetite, memory, movement, and pain.So far, solid studies suggest that these chemicals can:
Control vomiting in people undergoing cancer chemotherapy. Drugs based on two lab-made forms of THC are FDA-approved for this purpose.
Modestly reduce pain in people with conditions such as nerve damage, cancer, multiple sclerosis, and rheumatoid arthritis.
Reduce muscle spasms in people with multiple sclerosis. (There’s less evidence it helps muscle spasms in people with spinal cord injuries).
In addition, there’s some evidence that medical marijuana helps to:
Improve sleep in the short term for people with obstructive sleep apnea, fibromyalgia, chronic pain, or multiple sclerosis.
Increase appetite and decrease weight loss in people with HIV and AIDS.
Reduce tics in people with Tourette’s syndrome.
Reduce anxiety in people with social anxiety disorder.
Improve symptoms of post-traumatic stress disorder.
Can medical marijuana help with seizure disorders?
Medical marijuana received a lot of attention a few years ago when parents said that a special form of the drug helped control seizures in their children. Studies showed good enough results for the FDA to approve Epidiolex, made from a purified form of CBD, as a therapy for people with two rare seizure disorders, Lenox-Gastaut and Dravet syndromes.
