Cannabidiol (CBD) is one of many cannabinoids that can be found in hemp and marijuana, two types of cannabis plants.

CBD may help people with cancer manage some symptoms of the disease, as well as side effects of treatment. Scientists are also looking into how CBD could aid cancer treatment, but more research is needed before any conclusions can be made.

Cannabis, or marijuana, has enough tetrahydrocannabinol (THC) to get you high, but hemp does not. CBD is considered psychoactive, but it’s non-impairing and non-euphoric — unlike THC. However, some CBD products may have trace amounts of THC.

Let’s take a closer look at how CBD may help people with cancer.

There’s solid evidence supporting the idea that cannabinoids can reduce tumor growth in animal models of cancer. CBD may also enhance uptake or increase the potency of certain drugs used to treat cancer.

Here are some promising studies:

  • A 2019 review of in vitro and in vivo studies focusing on pancreatic cancer found that cannabinoids can help slow tumor growth, reduce tumor invasion, and induce tumor cell death. The study authors wrote that research into the effectiveness of different formulations, dosing, and precise mode of action is lacking and urgently needed.
  • A 2019 study indicated that CBD could provoke cell death and make glioblastoma cells more sensitive to radiation, but with no effect on healthy cells.
  • A large, long-term study of men within the California Men’s Health Study cohort found that using cannabis may be inversely associated with bladder cancer risk. However, a cause and effect relationship hasn’t been established.
  • A 2014 study in experimental models of colon cancer in vivo suggests that CBD may inhibit the spread of colorectal cancer cells.
  • A 2014 review of 35 in vitro and in vivo studies found that cannabinoids are promising compounds in the treatment of gliomas.
  • Research from 2010 demonstrated the efficacy of CBD in preclinical models of metastatic breast cancer. The study found that CBD significantly reduced breast cancer cell proliferation and invasion.

These are just a few studies addressing the potential of cannabinoids to help treat cancer. Still, it’s far too soon to say that CBD is a safe and effective treatment for cancer in humans. CBD shouldn’t be considered a substitute for other cancer treatments.

Some areas for future research include:

  • the effects of CBD with and without other cannabinoids like THC
  • safe and effective dosing
  • the effects of different administration techniques
  • how CBD works on specific types of cancer
  • how CBD interacts with chemotherapy drugs and other cancer treatments

Cancer treatments such as chemotherapy and radiation can produce an array of side effects, such as nausea and loss of appetite, which can lead to weight loss.

Research suggests that cannabinoids may ease neuropathic pain and nausea. THC has shown to improve poor appetite due to cancer and cancer treatment, while CBD can suppress it. CBD is also thought to have anti-inflammatory and anti-anxiety properties.

So far, only one CBD product has received Food and Drug Administration (FDA) approval.

That product is Epidiolex, and its only use is in the treatment of two rare forms of epilepsy. No CBD products have been FDA-approved to treat cancer or symptoms of cancer, or to ease side effects of cancer treatment.

On the other hand, two synthetic THC drugs have been approved to treat nausea and vomiting caused by chemotherapy. Dronabinol comes in a capsule (Marinol) and tincture form (Syndros) and contains THC. Nabilone (Cesamet) is an oral synthetic cannabinoid that acts similar to THC.

Another cannabinoid drug, nabiximols, is available in Canada and parts of Europe. It’s a mouth spray containing both THC and CBD and has shown promise in treating cancer pain. It’s not approved in the United States, but it is the subject of ongoing research.

If you’re considering using medical marijuana, talk to your doctor about how best to administer it. Smoking may not be a good choice for people with certain types of cancer.

CBD and other cannabis products come in many forms, including vape, tincture, sprays, and oils. They can also be found in candies, coffee, or other edibles.

Studies on the role of cannabinoids in the development of cancer have produced mixed results.

A 2010 study used a mouse model to study the effects of cannabinoids, THC specifically, on suppression of the immune system. The study found evidence that THC can, in fact, suppress the immune system, though whether that increases the risk of cancer is not well established.

When it comes to cancer prevention, CBD research has a long way to go. Scientists will have to conduct long-term studies of people using specific CBD products, controlling for frequency of use, dosing, and other variables.

The World Health Organization (WHO) says that CBD has a good safety profile and that negative side effects may be due to interactions with other medications. It states that there’s no evidence of public health-related problems from the use of pure CBD.

In 2017, a large review of studies found that CBD is generally safe, with few side effects. Among them are:

  • decreased appetite
  • diarrhea
  • tiredness
  • weight changes

More research is needed to understand other effects of CBD, such as whether it affects hormones. Researchers also want to know more about how CBD may increase or decrease the effects of other medications.

The review does suggest some concern that CBD may interfere with liver enzymes that help metabolize certain medications. That could lead to higher concentrations of these medications in the system.

CBD, like grapefruit, interferes with the metabolizing of certain medications. Talk to your doctor before using CBD, especially if you take a medication that comes with a grapefruit warning or one of the following:

The American Cancer Society supports the need for more research on cannabinoids for people with cancer.

CBD is a natural substance, but even natural substances must be approached with caution and due diligence.

There’s great variation in CBD products. Some CBD product labels make false health claims. In particular, CBD products purchased online have a high rate of mislabeling.

After analyzing 84 CBD products sold online, researchers found that about 43 percent had a higher CBD concentration than stated. About 26 percent had less CBD than claimed.

If you’re currently being treated for cancer, keep in mind that many substances can interact with other therapies. That includes CBD, other cannabinoids, or even dietary and herbal supplements.

Talk to your doctor about the potential benefits and risks of CBD, what to look for, and where to purchase it. Here are a few things to consider when choosing CBD products:

  • Products with hemp-derived CBD should have only trace amounts of THC.
  • Products with marijuana-derived CBD may contain enough THC to produce a high.
  • Avoid products that make over-the-top health claims.
  • Compare labels to see how much CBD is actually in the product.
  • It can take time to find the optimal dose and feel the effects, so a little patience is required. It’s a good idea to start with a small dose and increase it gradually.

You also want to be sure to purchase a high-quality CBD product from a reputable company. Before buying, research the company’s reputation by reviewing its BBB ratings and seeing if it has received a warning letter from the FDA.

The company should also offer a high level of transparency regarding the sourcing, manufacturing, and testing of its products.

CBD shouldn’t be used in place of other cancer treatments. We need more rigorous studies into the potential benefits and risks of CBD, dosing, administration, and how it affects other cancer therapies.

Currently, there are no FDA-approved CBD products for cancer. So, aside from Epidiolex for epilepsy, the products that are available haven’t been evaluated by the FDA.

Even so, some people are using cannabinoids to ease side effects of cancer treatment. Because CBD can interact with other cancer therapies, it’s best to check with your doctor before you start taking it.

Is CBD legal? The 2018 Farm Bill removed hemp from the legal definition of marijuana in the Controlled Substances Act. This made some hemp-derived CBD products with less than 0.3% THC legal at the federal level. However, CBD products containing more than 0.3% THC still fall under the legal definition of marijuana, making them illegal at the federal level. Some states have legalized CBD, so be sure to check state laws, especially when traveling. Also, keep in mind that the FDA has not approved nonprescription CBD products, and some products may be inaccurately labeled.