Medical cannabis and cannabinoids in raw or dried flowers, oils, capsules, powders, edibles, and topicals may reduce pain, and some evidence shows benefit with nausea and anxiety, but little evidence of improving treatment outcomes.
Cannabis and cannabinoids at a glance
On this page, we review the literature on cannabis’s benefits and risks. Overall, the evidence does not suggest that cannabis can improve cancer survival or prevent recurrence. However, there is modest to strong evidence that cannabis can help with side effects from cancer treatment, including nausea, anxiety, and pain.
Cannabis is a flowering plant. It is also known as marijuana, weed, or pot. Cannabinoids are chemicals found in cannabis. Two common cannabinoids you may hear referenced are tetrahydrocannabinol (THC) and cannabidiol (CBD). There are also several synthetic (man-made) versions of THC, including dronabinol and nabilone, which clinicians studied in the 1980s and 1990s. Some medical studies have used nabiximols, a plant extract with a THC:CBD ratio of 1:1 delivered as a sublingual spray.
Although people have used cannabis for thousands of years, the data on its health effects is scant. US law restricts research on cannabis, most studies on cannabis and cancer in the US are observational studies, not randomized trials, which limits the strength of the evidence. Many of the trials in publication were conducted before the 2000s with outdated forms of cannabis or comparison medications: for example, comparing cannabis to anti-nausea medications that aren’t used anymore. Finally, the forms of cannabis people use, and the doses they take, range widely.
CancerChoices ratings for cannabis and cannabinoids
We rate cannabis and cannabinoids on seven attributes, with 0 the lowest rating and 5 the highest. We rate the strength of the evidence supporting the use of cannabis or cannabinoids for a medical benefit, such as improving treatment outcomes or managing side effects.
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Keep reading about cannabis and cannabinoids
Reviewer
Dr. Abrams is past chief of the Hematology-Oncology Division at Zuckerberg San Francisco General Hospital, an integrative oncologist at the UCSF Osher Center for Integrative Medicine and professor of clinical medicine at the University of California San Francisco. He co-edited the Oxford University Press textbook Integrative Oncology with Andrew Weil, MD. He is a member of the NCI PDQ CAM Editorial Board. Dr. Abrams was president of the Society for Integrative Oncology in 2010 and is a CancerChoices advisor.
Last update: November 17, 2025
Last full literature review: October 2025
We are grateful to integrative oncologist and CancerChoices advisor Donald Abrams, MD, for his generous sharing of research articles and commentary.
CancerChoices provides information about integrative in cancer care, a patient-centered approach combining the best of conventional care, self care and evidence-informed complementary care in an integrated plan cancer care. We review complementaryin cancer care, complementary care involves the use of therapies intended to enhance or add to standard conventional treatments; examples include supplements, mind-body approaches such as yoga or psychosocial therapy, and acupuncture therapies and self-care lifestyle actions and behaviors that may impact cancer outcomes; examples include eating health-promoting foods, limiting alcohol, increasing physical activity, and managing stress practices to help patients and professionals explore and integrate the best combination of conventionalthe cancer care offered by conventionally trained physicians and most hospitals; examples are chemotherapy, surgery, and radiotherapy and complementary therapies and practices for each person.
Our staff have no financial conflicts of interest to declare. We receive no funds from any manufacturers or retailers gaining financial profit by promoting or discouraging therapies mentioned on this site.