Medical cannabis. Close-up of the hands of a 60-year-old male patient preparing cannabis (Cannabis sativa) for medication. The patient has metastatic lung cancer, and uses cannabis for symptomatic pain relief. Preliminary scientific evidence has indicated that cannabis might help to reduce nausea and vomiting during chemotherapy, and to reduce chronic pain and muscle spasms. The prescription of cannabis for medicinal purposes became legal in the UK in 2018, but it remains illegal to use the drug for recreational purposes.