Adding Cannabis to Standard Medicines Offers Better Nausea Control for People With Cancer
Adding oral cannabis extract to usual anti-nausea medicines was better for preventing nausea and vomiting in people receiving chemotherapy for cancer, according to a small Australian study published in the Journal of Clinical Oncology.
Cannabis is also called marijuana.
Key takeaways
Nausea and vomiting control was much better among people who took cannabis capsules plus the standard anti-nausea medicines than people who took just the nausea medicines.
People who took the cannabis capsules also had more troublesome side effects, including dizziness and feeling sedated or disoriented compared to people who didn’t take the cannabis capsules.
What the results mean for you
This study echoes the results of other studies showing that cannabis can help control nausea and vomiting caused by chemotherapy.
The study also highlighted some potential side effects that some people may have when using cannabis. For example, two people withdrew from the study after they took the first dose of cannabis because of the anxiety it caused.
It’s important to talk to your doctor about any cannabis products you would like to use, especially during treatment, to make sure it’s safe for you and won’t interact with any of the medicines you’re receiving.
If you are considering using cannabis, be sure you know what’s legal in your state or country. For instance, in the United States, marijuana is illegal nationwide under federal law. But most U.S. states have passed laws either legalizing the use of marijuana entirely or to treat certain medical conditions.
About the study
The study included 147 people receiving chemotherapy for cancer — about 40% had been diagnosed with breast cancer — who were having moderate to severe nausea while taking standard anti-nausea medicines.
The researchers randomly assigned the people to one of two groups: one group took a cannabis capsule; the other took a placebo capsule. The placebo capsule looked just like the cannabis one, but contained no cannabis or medicine. People in both groups continued to take their regular anti-nausea medicine. The people took the cannabis or placebo capsules three times a day for six days in a row, starting the day before they were to receive chemotherapy.
The cannabis capsules contained 2.5 milligrams (mg) of THC and 2.5 mg of CBD, both from the sativa strain.
Detailed results
The researchers recorded how many people had a complete response, which means they had no vomiting or retching and didn’t need to take a rescue medicine (a medicine that works quickly to ease nausea) in the five days after receiving chemotherapy.
The complete response rate was 24% for people who took anti-nausea medicine and cannabis and 8% for people who took only anti-nausea medicine.
People who took cannabis also had better results for other outcomes the researchers studied, including:
no use of rescue medicine: 28% vs. 9%
number of vomits per day: 0.2 vs. 0.5
quality of life-nausea score 67 vs. 48 (higher is better quality of life)
People who took cannabis reported more side effects, including:
feeling sedated: 18% vs. 7%
dizziness: 10% vs. 0%
feeling disoriented: 18% vs. 5%
“There are important barriers to using oral tetrahydrocannabinol (THC):cannabidiol (CBD) for [chemotherapy-induced nausea and vomiting] in routine clinical practice,” the researchers wrote. “These include adverse effects, cultural attitudes, and legal restrictions to the use of cannabinoids.”
Learn more
You can learn more about using cannabis to ease breast cancer treatment side effects by listening to the episode of The Breastcancer.org Podcast featuring Dr. Marisa Weiss discussing some of the research on cannabis, as well as the top three things to consider if you want to try medical cannabis.
Medical Cannabis for Breast Cancer Symptoms and Side Effects
Aug 11, 2023Peter Grimison et al. Oral Cannabis Extract for Secondary Prevention of Chemotherapy-Induced Nausea and Vomiting: Final Results of a Randomized, Placebo-Controlled, Phase II/III Trial. JCO 0, JCO.23.01836
— Last updated on January 20, 2025 at 3:10 PM