Medical cannabis has been legal in the UK since November 2018 for specific...

https://highstylife.com/can-i-qualify-for-medical-cannabis-if-i-had-bad-side-effects-from-meds/

Medical cannabis has been legal in the UK since November 2018 for specific conditions, but it is not a first-line treatment. You require a prescription from a specialist doctor, typically after other licensed options have failed to help