In 2018, UK cannabis law was updated through changes to the Misuse of Drugs...

https://shed-wiki.win/index.php/Why_Are_NHS_Medical_Cannabis_Prescriptions_So_Rare%3F

In 2018, UK cannabis law was updated through changes to the Misuse of Drugs Regulations 2001—not the Misuse of Drugs Act 1971. These changes allow specialist doctors to prescribe certain cannabis-based medicines like Sativex and Epidyolex under Schedule 2