Legal in the UK since 2018, medical cannabis is an option for some arthritis...

https://record-wiki.win/index.php/What_if_standard_arthritis_treatments_work_but_I_want_to_try_cannabis_anyway%3F

Legal in the UK since 2018, medical cannabis is an option for some arthritis patients, though it is never a first-line treatment. Access requires a formal specialist assessment, usually via private clinics