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

https://johnathanrsnj030.lucialpiazzale.com/does-medical-cannabis-help-with-sleep-disruption-during-marathon-training

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.