Medical cannabis became legal in the UK in 2018, but it is not a first-stop...

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

Medical cannabis became legal in the UK in 2018, but it is not a first-stop solution. It requires a specialist prescription, typically only after other standard treatments have failed to help