Since 2018, specialist-prescribed medical cannabis has been a legal UK option....

https://high-wiki.win/index.php/Why_Do_Some_People_Describe_Cannabis_Sleep_Effects_as_Gradual%3F

Since 2018, specialist-prescribed medical cannabis has been a legal UK option. For insomnia, it’s typically considered only after other treatments fail. Outcomes vary significantly, so consult a clinician to see if this pathway is right for you.