People with cancer who undergo radiation and chemotherapy frequently stop treatments rather than suffer the nausea, pain, and other unpleasant side effects. The effects of inhaled or smoked cannabis and oral THC administration has been studied in more than 35 clinical trials (six of these clinical studies were state sponsored) for the treatment of chemotherapy-induced nausea and vomiting. More than 40 clinical studies have looked at appetite modulation of cannabis and cannabinoids. Years before any state had authorized the medical use of cannabis, a 1991 Harvard Medical School study revealed that nearly half (44%) of U.S. oncologists were already recommending cannabis to their patients as a way of mitigating the side effects of cancer treatments17. In its 1999 review, the Institute of Medicine concluded that cannabis could be a valid alternative for many people living with cancer18. Specifically, the IOM notes, “[i]n patients already experiencing severe nausea or vomiting, pills are generally ineffective, because of the difficulty in swallowing or keeping a pill down, and slow onset of the drug effect19.”

Since the release of the IOM report, new research has been published which supports the use of cannabis to curb the debilitating effects of cancer treatment. In 2001, a review of clinical studies conducted in several states during the past few decades revealed that, in nearly 2,000 individuals with cancer, inhaled cannabis and oral cannabinoids were effective anti-emetics20. Other studies have concluded that the active components in cannabis produce palliative effects in cancer patients by preventing nausea, vomiting, and pain and by stimulating appetite. The tumor-fighting properties of cannabinoids have also been demonstrated in numerous laboratory studies and investigated in a successful Phase I clinical study looking at the safety of THC in patients with recurrent brain cancer. Researchers have observed that “these compounds have been shown to inhibit the growth of tumor cells in culture and animal models by modulating key cell-signaling pathways. Cannabinoids are usually well tolerated, and do not produce the generalized toxic effects of conventional chemotherapies21.”


Guzmán, M. Cannabinoids: potential anticancer agents. Nature Reviews Cancer 3, 745–755 (2003).