Prescribed cannabis? Know the rules. A medical defence covers the 2mcg/L THC...

https://evpowered.co.uk/feature/medical-cannabis-and-uk-driving-laws-what-ev-owners-must-know/

Prescribed cannabis? Know the rules. A medical defence covers the 2mcg/L THC limit, but legality isn't immunity. You must notify the DVLA if you're fit to drive. Remember: a prescription isn't a safety net—legal status never replaces your responsibility.