As of 2014, no studies exist that demonstrate the effects of hemp oil in humans, states the American Cancer Society. Hemp oil, marijuana oil and other forms of whole or crude marijuana are not approved by the FDA for medical use.
Drugs based on marijuana compounds, such as THC, are medically available and known to be effective in treating nausea and vomiting in chemotherapy patients, according to the American Cancer society. These drugs, which include dronabinol, can also boost appetite and reverse weight loss in HIV/AIDS patients. Mouth sprays derived from whole marijuana are prescribed in Europe and Canada to treat pain associated with cancer in addition to muscle spasms from diseases such as multiple sclerosis.
Conflicting evidence exists within the study of marijuana consumption in humans, says the American Cancer Society. The compound THC is noted for its therapeutic properties but is also linked to raised anxiety levels and even paranoia, while CBD, another prevalent compound in marijuana, lowers anxiety. Both the amount and effects of these two compounds can vary between individual marijuana strains. The method by which marijuana is consumed also has different effects; ingested marijuana compounds are processed by the liver and introduce additional psychoactive compounds into the body. This contrasts with inhaling marijuana compounds, which produces less of the additional psychoactive compound.