Since 2018, medical cannabis has been legal in the UK. It isn't 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. It isn't a first-line treatment for arthritis and requires a specialist assessment; most patients currently access it privately. It’s worth discussing with your GP to see if it's an option for you.