Using medical cannabis? You’re still bound by the 2mcg/L THC limit and DVLA...

https://city-wiki.win/index.php/Medical_Cannabis_and_Driving:_Your_DVLA_Responsibilities_and_the_Law

Using medical cannabis? You’re still bound by the 2mcg/L THC limit and DVLA rules. A medical defence exists, but it’s not a blank cheque. Legality doesn’t replace your duty to stay fit to drive