In 2018, UK cannabis law changed through updates to the Misuse of Drugs...

https://mega-wiki.win/index.php/What_Is_the_House_of_Commons_Library_Briefing_on_Medical_Cannabis%3F

In 2018, UK cannabis law changed through updates to the Misuse of Drugs Regulations 2001, not the Misuse of Drugs Act 1971. Since then, specialist doctors can prescribe cannabis-based medicines listed as Schedule 2 substances