Since 2018, medical cannabis has been a legal option in the UK when prescribed...

https://spark-wiki.win/index.php/Is_Medical_Cannabis_Considered_After_Other_Treatments_Fail_in_the_UK%3F

Since 2018, medical cannabis has been a legal option in the UK when prescribed by a specialist doctor. It is rarely a first-line treatment, typically considered only after standard sleep interventions have proven ineffective