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

https://blogfreely.net/gertonmhvf/can-my-gp-prescribe-medical-cannabis-in-the-uk-a-realistic-guide-to-the-pathway

Medical cannabis has been legal in the UK since 2018 for specific conditions. To be eligible, you need a specialist assessment and proof that you have already tried other treatments