People with multiple sclerosis can legally take a cannabis-based medicine.
This licensed medicine, called Sativex, is a mouth spray and contains two chemical extracts (THC and CBD) derived from the cannabis plant.
Under current laws in England and Wales, cannabis is not recognised as having any therapeutic value and anyone using the drug, even for medical reasons, could be charged for possession.
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The NHS warns that cannabis use carries a number of risks, such as impairing the ability to drive, as well as causing harm to lungs if smoked and harm to mental health, fertility or unborn babies.
The All Party Parliamentary Group on Drug Policy Reform took evidence from 623 patients, representatives of the medical professions and people with knowledge of how medical cannabis was regulated across the world.