Medical Marijuana and Cancer

Medically Reviewed by Sabrina Felson, MD on February 12, 2024
Written by Mary Jo DiLonardo
3 min read

Marijuana comes from the buds and leaves of the cannabis plant, which has been used for centuries as part of herbal remedies for many illnesses.

Cannabis is illegal in the U.S. under federal law, but the use of medical marijuana is legal in many states and some states have legalized recreational use. Some studies have found that it might help ease some of the symptoms and side effects of cancer treatment.

Marijuana has compounds called cannabinoids, which can cause drug-like effects on the body. The two most active and most studied are delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD).

THC causes marijuana's "high" feeling. It also may help ease pain, nausea, and inflammation.

CBD may ease pain, inflammation, and anxiety without causing the high.

Studies have looked at the possible benefits medical marijuana can have on cancer symptoms and treatment side effects.

Nausea and vomiting. A few small studies have found that smoking marijuana can ease these side effects of chemotherapy. The FDA has also approved dronabinol (Marinol, Syndros) and nabilone (Cesamet), man-made cannabinoids, to treat these symptoms when other nausea medications don’t work.

Pain. Some studies have found that smoked marijuana can ease cancer-related pain. It binds to cannabinoid receptors in the brain and other parts of the body.

Marijuana may also ease inflammation, which can also help with pain.

Nerve pain. Neuropathy is weakness, numbness, or pain caused by nerve damage. It can happen as a result of chemotherapy or other cancer treatments. A few studies have found that smoking marijuana can help this specific type of nerve pain.

Appetite and weight loss. Dronabinol is FDA-approved for loss of appetite in people with AIDS, but not specifically for cancer. There are some small studies that show marijuana may also help improve appetite for people with cancer.

Medical marijuana comes in several forms, including:

  • Dried leaves or buds for smoking
  • Edible products, like cookies, brownies, or candies
  • Oils for vaporizing or mixing into hot drinks or food
  • Creams that can be applied on the skin
  • Sprays for your mouth
  • Pills and capsules 

Some forms of marijuana are shown to work better than others to fight cancer symptoms or treatment side effects.

Side effects are possible from the marijuana itself. You could have:

Marijuana with THC can give you a "high" that can make you feel confused and give you less control over your movement. It may also trigger anxiety and paranoia.

If you’re considering medical marijuana, these are your next steps:

Know the law. Although marijuana is illegal in the U.S. on a federal level, each state has different laws about medical marijuana use, and those laws are changing regularly. Find out what the law says where you live.

Talk to your doctor. Your health care team can tell you whether medical marijuana might be a good option for you. Be sure to tell your doctor about all the drugs and supplements you’re taking. That information may be able to help them figure out which form of marijuana could help you.

You'll need to be certified to get it. Your doctor can help you with that.