Medical cannabis has been legal in the UK since 2018 for specific conditions....

https://record-wiki.win/index.php/How_do_clinics_decide_if_medical_cannabis_is_appropriate_for_you%3F

Medical cannabis has been legal in the UK since 2018 for specific conditions. Obtaining a prescription requires a formal assessment by a specialist doctor. You must provide medical records confirming at least two failed prior treatments