Medical cannabis has been legal in the UK via private clinics since 2018....

https://smoothdecorator.com/navigating-the-clinical-pathway-what-runners-must-ask-before-prescribed-treatment/

Medical cannabis has been legal in the UK via private clinics since 2018. Eligibility depends on your specific condition and prior treatments. If you are a competitive athlete, note that WADA still prohibits THC during in-competition periods.