Overview

Questions and Answers About Cannabis and Cannabinoids

What is Cannabis?

Cannabis, also known as marijuana, is a plant first grown in Central Asia that is now grown in many parts of the world. The Cannabis plant makes a resin (thick substance) that contains compounds called cannabinoids. Some cannabinoids are psychoactive (affects your mind or mood). In the United States, Cannabis is a controlled substance and has been classified as a Schedule I agent (a drug with a high potential for abuse and no accepted medical use).

Hemp is a mixture of the Cannabis plant with very low levels of psychoactive compounds. Hemp oil or cannabidiol (CBD) are made from extracts of industrial hemp, while hemp seed oil is an edible fatty oil that contains few or no cannabinoids. Hemp is not a controlled substance.

For information on medicinal Cannabis products, see the General Information section of the health professional version of Cannabis and Cannabinoids.

Clinical trials that study Cannabis for cancer treatment are limited. To start a clinical trial with Cannabis in the United States, researchers must file an Investigational New Drug (IND) application with the FDA, have a Schedule I license from the U.S. Drug Enforcement Administration, and have approval from the National Institute on Drug Abuse.

By federal law, possessing Cannabis (marijuana) is illegal in the United States unless it is used in approved research settings. However, a growing number of states, territories, and the District of Columbia have passed laws to legalize medical and/or recreational marijuana. (See Question 3).

What are cannabinoids?

Cannabinoids, also known as phytocannabinoids, are chemicals in Cannabis that cause drug-like effects in the body, including the central nervous system and the immune system. Over 100 cannabinoids have been found in Cannabis. The main psychoactive cannabinoid in Cannabis is delta-9-THC. Another active cannabinoid is cannabidiol (CBD).

Cannabinoids may help treat the side effects of cancer and cancer treatment.

If Cannabis is illegal, how do some cancer patients in the United States use it?

Although federal law prohibits the use of Cannabis, the map below shows the states and territories that have legalized Cannabis for medical use. Some other states have legalized only one ingredient in Cannabis, such as cannabidiol (CBD), and these states are not included in the map. Medical marijuana laws vary from state to state.

A map showing the U.S. states and territories that have approved the medical use of Cannabis.

How is Cannabis given or taken?

Cannabis may be taken by mouth (in baked goods or as an herbal tea) or may be inhaled. When taken by mouth, the main psychoactive part of Cannabis (delta-9-THC) goes through the liver and is changed into a different psychoactive chemical (11-OH-THC).

When Cannabis is smoked and inhaled, cannabinoids quickly enter the bloodstream. The psychoactive chemical (11-OH-THC) is made in smaller amounts than when taken by mouth.

Clinical trials are studying a medicine made from an extract of Cannabis that contains specific amounts of cannabinoids. This medicine is sprayed under the tongue.

Have any laboratory or animal studies been done using Cannabis or cannabinoids?

In laboratory studies, tumor cells are used to test a substance to find out if it is likely to have any anticancer effects. In animal studies, tests are done to see if a drug, procedure, or treatment is safe and effective in animals. Laboratory and animal studies are done before a substance is tested in people.

For information on laboratory and animal studies done using cannabinoids, see the Laboratory/Animal/Preclinical Studies section of the health professional version of Cannabis and Cannabinoids.

Have any studies of Cannabis or cannabinoids been done in people with cancer?

No ongoing studies of Cannabis as a treatment for cancer in people have been found in the CAM on PubMed database maintained by the National Institutes of Health.

Small studies have been done, but the results have not been reported or suggest a need for larger studies.

Cannabis and cannabinoids have been studied as ways to manage side effects of cancer and cancer therapies.

Nausea and vomiting

Cannabis and cannabinoids have been studied in the treatment of nausea and vomiting caused by cancer or cancer treatment:

Newer drugs given for nausea caused by chemotherapy have not been compared with Cannabis or cannabinoids in cancer patients.

There is growing interest in treating children for symptoms such as nausea with Cannabis and cannabinoids, but studies are limited. The American Academy of Pediatrics has not endorsed Cannabis and cannabinoid use because of concerns about its effect on brain development.

Appetite

The ability of cannabinoids to increase appetite has been studied:

Pain relief

Cannabis and cannabinoids have been studied in the treatment of pain:

Anxiety and sleep

Cannabis and cannabinoids have been studied in the treatment of anxiety.

Have any side effects or risks been reported from Cannabis and cannabinoids?

Side effects of Cannabis and cannabinoids can include:

Both Cannabis and cannabinoids may be addictive. Symptoms of withdrawal from cannabinoids include:

These symptoms are mild compared with symptoms of withdrawal from opiates and usually go away after a few days.

Studies on cancer risk from Cannabis use

Studies on the risk of various cancers linked to Cannabis smoking have shown the following:

Larger studies that follow patients over time are needed to find if there is a link between Cannabis use and a higher risk of testicular germ cell tumors.

Studies on Cannabis use and impact on cancer treatment

Few studies have been done to find out how Cannabis interacts with conventional treatment. A retrospective observational study in Israel showed that Cannabis reduced the effect of immunotherapy. A prospective observational study of immunotherapy and Cannabis in patients with metastatic cancer reported that the Cannabis users did not benefit from immunotherapy as much as those who did not use Cannabis.

Are Cannabis or cannabinoids approved by the U.S. Food and Drug Administration for use as a cancer treatment or treatment for cancer-related symptoms or side effects of cancer therapy?

The U.S. Food and Drug Administration (FDA) has not approved Cannabis or cannabinoids for use as a cancer treatment.

Cannabis is not approved by the FDA for the treatment of any cancer-related symptom or side effect of cancer therapy.

Two cannabinoids (dronabinol and nabilone) are approved by the FDA for the treatment of nausea and vomiting caused by chemotherapy in patients who have not responded to antiemetic therapy.

Current Clinical Trials

Use our clinical trial search to find NCI-supported cancer clinical trials that are accepting patients. You can search for trials based on the type of cancer, the age of the patient, and where the trials are being done. General information about clinical trials is also available.

This originally appeared at https://www.cancer.gov/about-cancer/treatment/cam/patient/cannabis-pdq