Possible Benefits of Cannabis for People with Cancer

People who have certain symptoms of cancer or side effects of cancer treatment might benefit from using cannabis. Relieving or reducing symptoms and side effects can lead to overall better quality of life for people with cancer and their caregivers. Managing symptoms and side effects well can also reduce the number of emergency room visits and hospital readmissions for things like dehydration due to nausea and vomiting, or uncontrolled severe pain.

Keep in mind that cannabis products can also have harmful effects. If you are interested in trying cannabis for yourself or a loved one who has cancer, it’s important to learn as much as you can about it. Talking with your doctor or cancer care team about the types, forms, doses, risks, and benefits can help you make an informed decision and know what to expect.

Your state’s laws​ about cannabis matter, even if you’re using cannabis for medical purposes. State laws are rapidly changing, so it’s important to know where to go for information. State laws will tell you whether cannabis is legalized for medical purposes or recreational use, or both. In states that have legalized cannabis, there are typically limitations on who can use it, along with where and how it can be used. State laws also explain how and where cannabis can be purchased legally, and many include a list of approved cannabis dispensaries and other retailers.

Does cannabis treat or cure cancer?

No, cannabis does not treat or cure cancer. Studies have not shown cannabis can stop or slow the growth of cancer cells. Experts at the American Society for Clinical Oncology (ASCO) have developed a guideline for cancer doctors (oncologists) who treat adults with cancer. The guideline states that cannabis should not be used as a treatment for cancer unless it’s being studied in a clinical trial.

What symptoms and side effects can cannabis treat?

The US Food and Drug Administration (FDA) and other experts have looked at the benefits and harms of cannabis and continue to study them. The FDA lists the following accepted medical uses of cannabis for problems that are commonly reported by people with cancer.

• Pain
• Nausea and vomiting
• Anorexia (loss of appetite)
• Stress and anxiety
• Sleep problems

The strongest benefits have been shown when cannabis is used to help relieve pain, nausea and vomiting, and loss of appetite.

Cannabis products come in many different forms and can be made from different varieties of cannabis plants, with differing levels of THC and CBD. It’s important to talk to you cancer care team about which options are best for the symptoms and side effects you have. Keep in mind that there are many other kinds of medicines and therapies that can help manage these effects as well.

Cannabis for pain relief

Cannabis has been used with other medicines to help manage cancer pain. Interest in using cannabis for cancer pain is increasing. There are a few reasons for this:

• Some people have trouble tolerating other types of pain medicines, or there is concern about pain medicines being safe for them because of other health problems. For example, some pain medicines can be harmful for people who have kidney problems.
• Sometimes a person is on many different medicines and treatments that may interact with each other.
• Some people may choose not to take opioids and other pain medicines because they are concerned about addiction.

Studies show mixed results in how effective cannabis is for pain in general. It has been found to be most effective for cancer pain and for nerve (neuropathic) pain. How cannabis is taken and the type of cannabinoids it contains (THC, CBD, or both) can greatly affect how it’s used to manage pain and what effects it can have on pain.

To help relieve pain for people who haven’t used cannabis in the past, experts recommend low-dose, non-inhaled cannabis products. Ingested, sublingual, and topical forms of cannabis are preferred. People who have experience using cannabis may be able to start at higher doses or take more frequent doses.

Cannabis to control nausea and vomiting

Nausea and vomiting are among the most common side effects reported by people getting cancer treatment. Anti-nausea medicines, called antiemetics, can be very effective. These include drugs like ondansetron. But sometimes antiemetics aren’t enough, or a person can’t take them for certain reasons. In these cases, cannabis may be considered.

A product that includes both THC and CBD might be more effective than others for nausea. But keep in mind that doses can vary widely. A certain type and dose of cannabis that helps reduce nausea for one person may be too much or not enough for someone else. 

Types of cannabis that might help reduce nausea are generally available in licensed dispensaries in states that consider cannabis legal for medical purposes. Whether you can buy the products without an order or prescription from a doctor depends on the state laws where you live and are being treated for cancer.

There are 2 prescription cannabis medicines approved by the US Food and Drug Administration (FDA) for use in treating nausea and vomiting from chemotherapy: dronabinol and nabilone. Both require a doctor’s prescription and are available at most pharmacies, even in states where medical cannabis is illegal.

• Dronabinol (Marinol) is a medicine containing delta-9-tetrahydrocannabinol (THC) and is approved to treat nausea and vomiting caused by cancer chemotherapy.
• Nabilone (Cesamet) is a synthetic cannabinoid that acts much like THC. It can be taken by mouth to treat nausea and vomiting caused by cancer chemotherapy when other drugs have not worked.

Cannabis as an appetite stimulant

People with cancer can experience a loss of appetite (anorexia) due to the cancer or its treatment. If anorexia isn’t managed well, a person may not get enough nourishment. This can lead to a serious condition called cachexia that involves both weight loss and muscle wasting.

Studies show people with cancer who have anorexia often report improved appetite when they use cannabis. For example, people with advanced cancer who have been part of small studies using THC have reported improved taste and appetite. However, there is very little research on whether CBD might increase appetite or help a person gain weight.

Along with helping nausea and vomiting, dronabinol is approved to help manage weight loss and poor appetite in people who have HIV/AIDS. Some experts recommend its use to help with cancer-related weight loss and anorexia as well.

Cannabis to reduce anxiety

Many people have anxiety in response to stressful situations. People with cancer are no different, and they may have higher anxiety at different times during their cancer experience. Studies have shown that  the main reason people give for using cannabis is to reduce anxiety.

Certain cannabis products, especially those containing Cannabis indica, generally work well to reduce anxiety. Indica products usually include CBD, which has been shown to be helpful in managing anxiety. However, products with high amounts of THC can actually increase anxiety.

Cannabis to help insomnia

Sleep is very important for overall health. People with cancer often report insomnia and other problems when trying to fall asleep, stay asleep, or go back to sleep. Cancer-related fatigue and pain, or side effects from treatment, can add to nighttime sleep problems. 

Various medicines can be used to help with sleep problems. Some people use or turn to cannabis as an alternative or combined with other sleep medicines. This is understandable, since some types of cannabis tend to calm the mind and make a person feel more relaxed.

Typically, products made from the indica cannabis plant can have a calming, relaxing effect. Products that have CBD added can also have a relaxing effect.  Studies show that CBD used in higher doses for short periods of time might be helpful in reducing the time needed to fall asleep and increasing the amount of sleep time. However, some experts don’t recommend using cannabis on a long-term basis because it may have a negative effect on the quality of your sleep. Other studies suggest that stopping cannabis after prolonged use can make sleep problems worse.

Using cannabis should always be discussed with a doctor to be sure it’s a safe option and to know what you might expect.