Cannabinoids are the active compounds in cannabis; the most studied are THC (psychoactive) and CBD (non-intoxicating). In cancer care they are used as complementary symptom therapies. FDA-approved prescription cannabinoids (dronabinol, nabilone) are used for chemotherapy-related nausea and vomiting that don’t respond to standard drugs, and for appetite/weight issues in some settings. Some patients use medical cannabis for nausea, pain, appetite or sleep. Evidence is strongest for chemotherapy nausea and for certain kinds of pain, and weaker or mixed for many other claims. Importantly, laboratory and popular claims that cannabis or CBD “cures cancer” are not supported by human clinical evidence, and cannabinoids can interact with other medicines (including some cancer drugs) and affect the immune response. Laws, product quality and dosing vary widely.
Prescription cannabinoids (dronabinol, nabilone) are taken by mouth under medical supervision. Medical-cannabis products (oils, capsules, inhaled, edibles) vary by state law and are best used with guidance from the oncology team, who can check interactions and advise on THC/CBD content, dosing and route.
Effects and side effects depend heavily on the product, dose and route. Start low and go slow, and keep the care team informed, especially during active treatment. These are symptom therapies used alongside standard care.