Anorexia and cachexia are diagnosed in more than two-thirds of all cancer patients with advanced disease and are independent risk factors for morbidity and mortality. Anorexia, nausea, and vomiting often are described as more significant inhibiting factors for the quality of life of cancer patients than even intense pain.
In 1986, delta-9-tetrahydrocannabinol (THC), the main effective constituent of cannabis, was licensed as an anti-emetic drug in cancer patients receiving chemotherapy. In addition, in clinical studies, THC has shown significant stimulation of appetite and an increase in body weight in HIV-positive and cancer patients.
The appetite-stimulating effect of cannabis itself has also been well documented in many anecdotal cases. There are strong indications that cannabis is better tolerated than THC alone because cannabis contains several additional cannabinoids, like cannabidiol (CBD), which antagonize the psychotropic actions of THC but do not inhibit the appetite-stimulating effect.