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

https://tango-wiki.win/index.php/What_Is_Sativex_and_Who_Can_Get_It_in_the_UK%3F

In 2018, UK cannabis law changed through an update to the Misuse of Drugs Regulations 2001—not the Misuse of Drugs Act 1971—allowing specialist doctors to prescribe cannabis-based medicines under Schedule 2