Does CBD Help Cancer?

Over 1.7 million new cases of cancer are diagnosed every year in the United States. For many of these individuals, they don’t just have the symptoms of their disease to deal with. A cancer diagnosis often initiates fears and concerns than can lead to anxiety, depression, and reduced quality of life. Further, once they begin treatment, chemotherapy introduces a new set of difficult side effects to manage, such as pain and fatigue.

Living with and treating cancer takes a toll, and not everyone responds adequately to traditional treatment. Worse, some treatment—like opioids for pain—can put the individual at risk of dependence.

Cancer researchers continue to seek out novel ways to reduce these effects. One promising option is CBD. CBD, a non-psychoactive chemical compound found in cannabis, appears to provide a wide range of benefits that are particularly beneficial for cancer patients. Studies show CBD relieves pain, chemotherapy-induced nausea, anxiety, and sleep problems. Early research indicates CBD may even cause or contribute to cancer cell death, leading many to view it as a potential anticancer drug. More research needs to be done, but for now, many cancer patients are turning to CBD oils as a way to alleviate other symptoms of living with cancer.

What is CBD?

CBD is one of over 100 chemical compounds found naturally in the cannabis plant. These compounds are called cannabinoids, and they mimic the structure of the endocannabinoids your own body produces, as part of your endocannabinoid system.

The main function of the endocannabinoid system (ECS) is to keep your body in a state of balance. It helps regulate your mood, immune system, appetite, sleep, and pain response. The ECS does this by way of cannabinoid receptors located in your central and peripheral nervous systems. When endocannabinoids, or external cannabinoids like CBD, bind to these receptors, the interaction helps bring the body back into balance.

This is why CBD produces such a wide range of benefits, from pain and anxiety relief to reduced inflammation and nausea. The CBD, in conjunction with your ECS, targets receptors in the areas that are out of balance, creating a response that brings them back in line. For example, if you take CBD for pain, the CBD activates receptors in the area of your body experiencing the pain, while also engaging receptors in your brain to adjust your brain’s perception of that pain.


You may be wondering if CBD is the same as THC, another cannabinoid that comes from the cannabis plant. THC is well-known among the cancer community, as medical marijuana is often prescribed to treat the pain, depression, and nausea associated with cancer treatment. However, the psychoactive properties of THC produce a feeling of being “stoned” that can interact with the individual’s ability to function normally. For some people, THC also induces feelings of anxiety and paranoia.

Because CBD is non-psychoactive, it does not create a “high” like THC. In fact, CBD actually counteracts the high of THC, reducing the feeling of being stoned, along with any accompanying anxiety or paranoia. For people who want to avoid the psychoactive symptoms of THC, but maintain the benefits, CBD provides a suitable alternative.

There’s also the problem of legality with THC. Medical marijuana is only legalized in a portion of states, and users typically need a prescription. Unlike THC, CBD is legal in all fifty states and can be easily purchased online and in many local health stores.

All of this makes CBD an attractive option for cancer patients seeking the same relief of marijuana, but without the high or potential legal obstacles.

Benefits of CBD for Cancer

CBD research is a new and growing field. Thus far, however, the results are promising—particularly for cancer patients. Specifically, CBD can help cancer patients cope with the side effects of treatment, such as chemotherapy-induced nausea, pain, and sleep issues. There’s also evidence that CBD may be able to slow or prevent cancer growth.

CBD provides chronic pain relief

Many individuals with cancer live with chronic pain. The medications most often prescribed for pain are opioids. These are highly habit-forming, which puts these patients at risk of addiction. They also have serious side effects, like sleepiness, constipation, nausea and vomiting. Despite the risk for addiction and side effects, opioids are extremely effective at relieving pain. Unfortunately, some cancer patients are unresponsive to opioids.

Due to its analgesic effects, CBD can be a preferred option for these patients. Plus, CBD doesn’t lead to dependence or tolerance. For those worried about putting themselves at risk of addiction, CBD can be a safer—yet just as effective—alternative. One study found CBD provided 30% more pain relief than either traditional medication or medical marijuana.

Sativex, an oral spray with equal parts THC and CBD, has proven both safe and effective for treating cancer pain. As the chart below demonstrates, negative symptoms were significantly less with long-term use of Sativex as opposed to other treatments, including medical marijuana:

sativex cbd vs medical marijuana for chronic pain relief among cancer patients

CBD lessens chemotherapy-induced nausea and vomiting

Chemotherapy is one of the most effective ways to kill cancer cells to date. Unfortunately, extreme side effects are common, such as fatigue, hair loss, and chemotherapy-induced nausea and vomiting (CINV). In fact, CINV symptoms are so common—and so severe—that they cause up to half of patients to delay or quit chemotherapy entirely.

As an antiemetic, CBD can significantly reduce CINV. One study treated patients with a daily oral spray, which contained either a placebo or a combination of CBD and THC. The CBD/THC spray reduced CINV symptoms by half.

Further, two separate systematic reviews of over 30 trials have found that CBD is significantly more effective in controlling nausea symptoms than other common antiemetic medications.  

CBD relieves anxiety and sleep problems

Some of the most common symptoms experienced by cancer patients include sleep problems. Typically, these present as chemotherapy-related fatigue, or some form of insomnia (difficulty falling or staying asleep). Problematically, poor sleep quality impairs the immune system’s ability to function, while also worsening mood and cognitive performance.

Fortunately, several studies have found that CBD improves sleep quality, by enabling patients to fall asleep easier and reducing their nighttime awakenings.

Sleep issues themselves are often linked to pain or anxiety, both of which are common among cancer patients. Estimates range, but roughly 20% of cancer patients have anxiety or depression. CBD can help with anxiety, too, by activating 5-HT1A receptors in the brain. This interaction appears to facilitate serotonin production, creating an antidepressant-like effect.  

CBD may slow or suppress tumor growth

CBD may also slow or stop tumor growth, according to a number of studies. Two studies focused on breast cancer found that CBD killed cancer cells, or otherwise slowed the growth of metastatic breast cancer. Similarly, CBD appears to inhibit tumor growth for liver cancer and glioblastoma.  

In some cases, it appears the CBD does not directly suppress the tumor growth. Instead, it helps by enabling the primary treatment to be more effective. For example, one study found combining CBD with anti-leukemia drugs made the drugs more effective at a lower dose.

As a natural anti-inflammatory, some researchers believe CBD may also have a preventative effect. There appears to be a causal link between inflammation and certain types of cancer, so a CBD regimen could potentially lower one’s risk for thyroid, brain, and prostate cancers.

CBD linked to increased survival rates for pancreatic cancer

In arguably the most exciting finding to come out of CBD research, a 2018 study found that CBD may actually increase cancer survival rates. The five-year survival rate for pancreatic cancer is 5%. Researchers split a group of mice with pancreatic cancer into two groups. One was treated with chemotherapy, while the other received a combination of CBD and chemotherapy. The group that received CBD survived nearly three times longer than the chemotherapy-only group.  

cbd and chemotherapy increased survival rates among mice with pancreatic cancer

Researchers found that activating a certain cannabinoid receptor, known as GPR55, appeared to boost cancer cell growth in the mice. They also found that CBD was a GPR55 antagonist. When they combined CBD with Gemcitabine (“GEM” in the image above), one of the most effective drugs in treating pancreatic cancer, the CBD inhibited the receptor. As a result, the Gemcitabine was more effective in slowing tumour cell growth, leading to the 300% higher survival rates.

It’s important to remember that this study was conducted on mice. More research still needs to be done to explore the efficacy of CBD in increasing cancer survival rates for humans.

Is It Safe to Use CBD Oil for Cancer?

Generally, CBD is very safe and has few to no side effects. However, when side effects occur, they’re most commonly among people who are taking other medication. Even then, side effects are rare, but they may include tiredness, dry mouth, nausea, diarrhea, or changes in appetite or blood pressure.

Because cancer patients are more likely to be taking other medications to manage their cancer, it’s extremely important to speak with your doctor before using CBD. They can advise you as to whether the CBD may interact negatively with your drugs (some studies show it increases the hepatic concentration of some drugs, leading to liver damage).

How to Use CBD Oil for Cancer

There are four main ways to consume CBD oil. Each of these methods is equally effective. People choose one method over another, mostly based on personal preference.


CBD vape oils are designed specifically to be inhaled through a vape pen or vaporizer. Inhalation of CBD provides the fastest relief, as the CBD enters the bloodstream directly through the lungs. Many individuals prefer inhaling CBD as they find the physical act of inhalation relaxing, they want to feel the effects as quickly as possible, and they like that the vape flavors mask the natural earthy flavor of CBD.

However, it is important to note that the effects of CBD last the shortest amount of time with inhalation, between 2 to 3 hours vs. the 4 to 6 hours offered by other methods of ingestion. For longer-lasting relief, we recommend one of the three methods below.


CBD oil tinctures require the user to place drops of the CBD oil beneath their tongue. With this method, onset may take a little bit longer than inhalation, but it is still fairly quick (around 5 to 20 minutes). People prefer sublingual tinctures as they can enjoy CBD without any other additives (such as the natural flavoring of CBD vape oils or CBD gummies), the dropper makes precise dosing easy, and they work quickly.

Topical application

CBD oil can also be applied topically to the skin, through creams, lotions, and gels. With this method of application, the CBD will not enter your bloodstream. Instead, the CBD will engage cannabinoid receptors through the skin. Many people prefer CBD topicals for managing pain, as rubbing the CBD cream into their skin affords them the opportunity to give themselves a massage.

One downside to topicals is that this method is naturally less precise than other methods. However, CBD topicals will always come with clear instructions for how to apply the CBD for desired effects.

Oral ingestion

CBD oil can also be eaten, through CBD edibles or by adding CBD oil to food or drink. You can also swallow CBD capsules, which resemble traditional pills or softgels, or eat CBD gummies.

With oral ingestion, it can take 30 to 90 minutes before you start feeling the effects, since the CBD has to travel through your digestive system before it enters your bloodstream. However, many people still prefer to eat CBD as they like the flavors of CBD gummies or, on the other hand, the lack of flavor provided by CBD capsules.

How Much CBD Oil to Take for Cancer

While CBD provides many benefits, ease of finding the right dose is not one of them. Finding your dose is arguably the hardest part of using CBD. Also, because CBD is not yet regulated by the FDA, no official dosing guidelines exist.

Most people use between 1mg to 6mg of CBD for every 10 pounds of their body weight. You can find the recommended dose of CBD for your body weight here.

The exact dose varies, based on the person’s body weight, personal body chemistry, and the intensity of their condition. Due to the severity of their symptoms, cancer patients typically have to use a higher amount of CBD.

When taking CBD, remember that it can take up to 90 minutes to feel the effects with oral methods. With other methods, the effects should be felt almost immediately, within a handful of minutes at most. As you begin your CBD regimen, start with the lowest dose for your body weight and slowly increase from there until you find one that’s effective.

How to Buy CBD Oil for Cancer

While CBD itself is safe, the industry is new and not yet regulated. If you are interested in trying CBD oil, take the following steps to ensure you buy quality CBD oil.

  • Only purchase from manufacturers who use third-party labs to test the safety of their ingredients. Third-party labs will test both the concentration of CBD and other cannabinoids, as well as the safety of other ingredients in the CBD oil. Manufacturers should make these safety certificates easily accessible to consumers, either online or with the product packaging.
  • Only buy CBD products sourced from hemp, not marijuana. CBD oils can be sourced from either hemp or marijuana. However, marijuana is not legal in all fifty states, and it typically contains higher amounts of THC. CBD oils sourced from hemp will contain 0.3% THC or less, so they will not produce a “high” or show up on a drug test for marijuana.
  • Avoid synthetic CBD. Along the same lines, CBD should come from pure hemp and contain no synthetic ingredients. Synthetic CBD is more likely to contain toxic ingredients and cause extreme side effects. Instead, choose CBD products made from 100% industrial hemp, locally grown in the USA, that only contain other organic or natural ingredients.
  • Read online reviews. Manufacturers will share customer reviews on their website. Read through these, not only to ensure the safety of the product, but also to assess the efficacy of the product for cancer specifically. Many customers will share what they are using the CBD for. You can also ask questions in online forums, like the Cancer subreddit, CBD subreddit, Cancer Chat, or American Cancer Society forums.
  • Consult your doctor. CBD can negatively interact with other medications you may be taking. Your doctor can advise you as to whether it is safe for you to try CBD, and they may also be able to provide additional recommendations around dosing or specific methods of ingestion.

Additional Resources

There’s a lot to explore with CBD, from different types of products to how it helps relieve various conditions. Learn more at the links below.