As of 2015, there have been no studies detailing the effects of hemp oil as cancer treatment. However, numerous studies found positive effects from the inhalation of marijuana, according to the American Cancer Society.
Studies have shown that smoking marijuana can help treat nausea and vomiting from chemotherapy, and the inhalation of smoked or vaporized marijuana can treat pain caused by damaged nerves, explains the American Cancer Society. In addition, marijuana extract users in clinical trials reported less reliance on pain medication. Scientists recently reported that THC and CBD, active compounds of marijuana, kill or slow the growth of certain laboratory-grown cancer cells.