Medical cannabis has been legal in the UK since 2018, but it isn't a first-line...

https://doctiplus.net/arthritis-and-medical-cannabis-can-uk-patients-get-a-prescription/

Medical cannabis has been legal in the UK since 2018, but it isn't a first-line treatment for arthritis. Access requires a specialist assessment, typically found through private clinics. If you’re considering it, do speak with a qualified professional.