CBD During Chemotherapy: Everything You Need to Know
CancerCancer Treatment

CBD During Chemotherapy: Everything You Need to Know

CBD During Chemotherapy: Everything You Need to Know
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Published on October 10, 2024
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Chemotherapy treats cancer by stopping cancer cells from growing and spreading, but it can also affect healthy cells, causing side effects like nausea, vomiting, fatigue, hair loss, and pain.

CBD (cannabidiol), a chemical found in the cannabis plant (which also produces the drug marijuana), has grown in popularity for many uses since the U.S. Congress legalized it in 2018.

 Experts estimate that anywhere from 4 to 24 percent of people with advanced cancer types are already using some kind of cannabis for their chemotherapy side effects.

CBD differs from THC, which can also be found in the cannabis plant. Whereas THC causes altered consciousness (a “high”), CBD doesn’t have the same psychoactive effects.

 Many products contain a combination of both, but an isolate CBD product contains pure CBD, with all THC removed.

Below, we’ll explore what the research says about CBD for chemotherapy side effects and how to use it safely.

How CBD Helps Chemotherapy Side Effects

To understand how CBD may provide relief for chemotherapy side effects, we must first look at the endocannabinoid system, or ECS. The endocannabinoid system partially regulates processes in your central nervous system by binding with certain receptors that affect pain perception, memory, appetite, and your immune system.

“CBD reacts with these receptors and can either increase activity in that receptor or potentially block and decrease activity,” says Leah Couture, MD, a palliative care physician at the University of Maryland Greenebaum Comprehensive Cancer Center in Baltimore.

So far, research studies on CBD in cancer are small and the results are mixed; experts can’t say with certainty that CBD lessens side effects.

 “We don’t have randomized clinical studies to determine whether it works,” says Liudmila Schafer, MD, an oncologist at Mercy Health System in St. Louis, who adds that more research with specific patient populations needs to be done.

Benefits of CBD in Chemotherapy

As research progresses, we may learn more about how CBD can help with some chemotherapy side effects as a part of an integrative approach to symptom management.

 Here’s what we know so far.

Reduced Nausea and Vomiting

Research shows that CBD-THC combinations improve nausea and vomiting side effects, but recent research on CBD alone is scarce.

 Sharyn Lewin, MD, an oncologist at Holy Name Medical Center in Teaneck, New Jersey, says her patients report that CBD sometimes helps decrease their nausea and vomiting, making treatment more tolerable.

Pain Relief Benefits

Most of the evidence for pain relief from CBD without THC is anecdotal — people taking chemo say it works for them — but researchers haven’t been able to replicate those results on a large scale in high-quality trials.

Like with nausea, many successful trials have focused on a CBD and THC combination therapy, however one small study showed that CBD-dominant products reduced pain as well THC-dominant options.

Other studies have shown CBD may reduce inflammation, which can decrease pain.

 “CBD may help manage pain, whether it's related to the chemotherapy itself, cancer, or other underlying conditions,” says Dr. Lewin. And some providers are considering use of CBD alongside opioid pain medications like morphine to lower the amount of narcotics needed for pain control.

Chemotherapy-Induced Fatigue

We don’t yet know how well CBD alone helps with chemotherapy-induced fatigue, but research shows a combination of THC and CBD can lower this side effect.

Appetite Stimulation and Weight Maintenance

Unlike THC, which famously causes the “munchies,” CBD may actually suppress appetite, according to one review of 11 small studies. Some people had an increased appetite with CBD, others decreased, and some had no change. But overall, on average, appetite levels decreased with CBD alone.

That said, these studies were small and reported a risk of bias, so experts say more research needs to be done to know for sure.

 The only other caveat: If CBD successfully decreases side effects like nausea or pain, appetite may increase as a result.

Is CBD Safe for Chemotherapy Patients?

In 2018, the World Health Organization labeled CBD as “generally well tolerated.”

 But experts don’t yet have long-term safety information, as most clinical trials have only assessed it up to 14 weeks.

“CBD is generally considered safe for most individuals, including chemotherapy patients,” says Lewin. But, she adds, it can interact with some chemotherapy drugs (and other medications) by affecting liver enzymes that process them, which could potentially alter the effectiveness of chemotherapy.”

The other safety concern with CBD lies in its lack of regulation. CBD products aren’t held to the same standard as prescription medications, so you may not know how much you’re getting with each dose.

  “For some people, CBD may also [cause] side effects, including dry mouth, diarrhea, reduced appetite, and drowsiness, and should be used with caution,” says Dr. Couture.

The U.S. Food and Drug Administration (FDA) has approved two CBD-THC combination medications for chemotherapy-associated side effects: dronabinol (Marinol) and nabilone (Cesamet). The sole CBD-only medication approved by the FDA is called Epidiolex, which is used to treat seizures.

Although Congress legalized CBD products, each state has their own laws on CBD use, so be sure to check your state restrictions before you decide to try it.

How to Use CBD During Chemotherapy

CBD comes in a few different forms, and each product will come with instructions on its use. Since research is lacking, though, providers don’t have much information on dosage or recommendations on how to take them.

“There are anecdotal (individual) experiences, but no collective knowledge on the right prescriptions,” says Dr. Schafer.

 But, if you want to try CBD for chemotherapy side effects, Lewin recommends asking your health team to consult a palliative care provider, who can help guide you in its use.

Available CBD Products

For medical use, CBD typically comes as a cream, gel, or oil.

 If CBD is legal in your state, you can find it in several other forms, including:

  • Tinctures
  • Edibles
  • Lotions
  • Capsules
  • Patches
  • Vapes

How to Use CBD Oil 

CBD oil can be swallowed (oral), placed under the tongue (sublingual), or rubbed onto the skin (topical).

 No standard dosage guidelines for CBD exist yet, and your ideal dosage will depend on how much you weigh, your metabolism, and the type of CBD you choose.

Daily amounts can range anywhere from 5 milligrams (mg) to over 100 mg. “Initially, a CBD dose should be low, around 5 mg. If taken in an edible form, it may take a few hours before you notice an effect, so avoid taking additional doses, as they could build up,” says Couture.

Remember the following, when shopping for CBD products:

  • Check the label for a purity or quality statement from its manufacturer.
  • Make sure the product lists a specific dose in milligrams (mg).
  • Look for the words “broad spectrum” or “isolate,” as these should have less THC than a full-spectrum option.

Tips for Safe Usage

“Because it can cause drowsiness, I generally recommend taking [CBD] in the evening when you are not planning on driving,” says Couture, who adds that people with conditions like osteoporosis may want to have a family member around to help make sure they stay safe and avoid falls if they become unsteady.

Before you start using CBD, talk it over with your healthcare provider. They can check for known interactions with your other medications (including your chemotherapy), monitor for side effects, and offer general guidance.

Legal Implications: CBD Use for Cancer Patients in Different Regions

The legal implications around CBD are complex. Congress legalized the use of hemp in 2018, which includes CBD, but the U.S. Drug Enforcement Agency (DEA) still lists marijuana and its cannabinoids (like CBD) as Schedule I controlled substances, which means they can’t be legally prescribed, owned, sold, or taken under federal law, unless being used for research.

Even so, the states have been passing laws regarding CBD, and many states allow the sale and possession of a wide range of CBD products. You can check your state’s CBD laws through the National Conference of State Legislatures.

 When in doubt, ask your doctor about any CBD restrictions in your area.

The Takeaway

CBD may alleviate chemotherapy side effects like nausea, pain, and fatigue because of its interaction with the endocannabinoid system in your body. Although research is limited and results are mixed, many people find some relief with CBD during cancer treatment. Talk to your healthcare team to see if CBD might be a safe and suitable option for you.

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