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

https://www.cast-bookmarks.win/since-2018-medical-cannabis-has-been-legal-in-the-uk-getting-a-prescription

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