Since 2018, medical cannabis has been legal in the UK but is never a first-line...

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

Since 2018, medical cannabis has been legal in the UK but is never a first-line arthritis treatment. Access requires specialist assessment, usually via private clinics, after other therapies have failed. Always discuss options with a professional.