Cannabis that contains high levels of THC can cause panic attacks, hallucinations and paranoia.
There are trials looking at whether Sativex can help with cancer pain that has not responded to other painkillers.
We need more research to know if cannabis or the chemicals in it can treat cancer.
How you have it
The results of one trial showed that Sativex did not improve pain levels. You can read the results of the trial on our clinical trials website.
There has been a lot of interest into whether cannabinoids might be useful as a cancer treatment. The scientific research done so far has been laboratory research, with mixed results, so we do not know if cannabinoids can treat cancer in people.
A drug called dexanabinol which is a man made form of a chemical similar to that found in cannabis has been trialled in a phase 1 trial. This is an early trial that tries to work out whether or not the drug works in humans, what the correct dose is and what the side effects might be. The results are not available yet. You can read about the trial on our clinical trials database.
Cancer nausea and vomiting
There have been some studies that show that CBD, alone or together with THC, may relieve pain, insomnia, or anxiety, but these studies were not specific to people with cancer. While no studies to date have shown that CBD eases these side effects specifically in people with cancer or people receiving cancer treatment, some people with cancer have reported benefits in taking CBD, such as helping with nausea, vomiting, depression, and other side effects. According to ASCO guidelines, your doctor may consider prescribing cannabinoids for chronic pain management if you live in a state where it is legal. However, ASCO guidelines state that there is not enough evidence to support the use of cannabinoids for preventing nausea and vomiting in people with cancer receiving radiation therapy or chemotherapy.
You may find stories online of people discussing the benefits of CBD as a cancer treatment or as relief for side effects. Please remember that such personal stories, while they may be well-meaning, are shared without scientific study and do not constitute evidence. The safety and efficacy of CBD for people with cancer still has to be proven in large, randomized, controlled clinical trials.
To date, no large-scale studies have shown CBD to have benefits for the treatment of people with cancer. Most studies that have been done evaluating CBD as a cancer treatment were in mice or in human cells in the lab. For instance, there are some studies that have shown that CBD inhibits the growth of cancer cells in mice with lung cancer or colon cancer. Another study showed that CBD, together with THC, killed glioblastoma cancer cells in the lab. However, no studies have been conducted in people with cancer.
Can CBD help people with cancer?
There are 2 synthetic cannabis medications, nabilone (Cesamet) and dronabinol (Marinol or Syndros), that are FDA-approved to treat nausea and vomiting related to chemotherapy. These medications are made in a laboratory.
CBD comes from cannabis plants called hemp that are specifically grown with high levels of CBD and low levels of THC. Cannabis plants grown with high levels of THC are usually called marijuana. CBD comes from oil that is extracted from the cannabis plant. That oil can then be ingested as a liquid, a capsule, a gummy, or inhaled through vaping. It can also be added as an ingredient in such products as lotions and skin patches.
You may also be wondering if CBD is legal in your area. Some states allow the sale and possession of cannabis, including CBD and THC, for medical and recreational use. Others have stricter regulations, so state-by-state laws should always be learned before transporting CBD across state lines. Things are more complicated at the federal level. In 2018, the U.S. government recognized that hemp can be grown and manufactured legally as part of the Farm Act. Hemp can be used to make things like rope and clothing, in addition to CBD oil. In other words, hemp is no longer a controlled substance, which means it is not regulated by the government. This means that consumers have to evaluate the safety and quality of CBD products on their own. Some CBD, for example, may have much higher levels of THC than what is labeled.
Studies to answer this question are underway. Some scientists are studying whether CBD could relieve some of the side effects of cancer and its treatment, such as pain, insomnia, anxiety, or nausea. Other scientists are studying whether CBD could potentially slow or stop the growth of cancer.
Dr. Raghunathan: The new law allows New Yorkers 21 and over to have up to three ounces of marijuana for recreational use. Using and selling marijuana are both legal, except in schools, workplaces, or in cars. The law also allows New Yorkers up to 24 grams of concentrated cannabis products, including products containing CBD, which is one of many chemicals extracted from the cannabis plant. CBD is different from delta-9-tetrahydrocannabinol, also known as THC, which is another chemical extracted from the cannabis plant.
You and your MSK care team should make a joint decision on using cannabis.
Should people with cancer consider using marijuana for anxiety or to ease side effects from treatment?
Cannabis, also known as marijuana, is used to treat some symptoms related to cancer. It’s made from the flowers, leaves, and resin (sticky chemical) of the Cannabis sativa plant.
Dr. Raghunathan: While legalization and regulation may change the accessibility and/or quality of all cannabis products, it doesn’t change the lack of scientific evidence. Unfortunately, we still don’t know enough about the benefits of these products for people with cancer. There is a lot of research happening in Canada and Australia because regulations around its use there have changed. It will be interesting to see what comes out of that. In the meantime, you and your doctor should discuss the potential benefits and harms of using anything with cannabis for medical purposes.
We asked Nirupa Raghunathan, an integrative medicine doctor at Memorial Sloan Kettering, and pharmacist Jason Hou, who manages MSK’s About Herbs database, to share what people with cancer should know before trying marijuana or its cousin, cannabidiol (CBD).