Prescribed cannabis and driving: a medical defence exists for the 2mcg/L THC...

https://bizzmarkblog.com/the-motorists-guide-to-medical-cannabis-dvla-rules-section-5a-and-staying-legal/

Prescribed cannabis and driving: a medical defence exists for the 2mcg/L THC limit, but it’s no golden ticket. You must still meet DVLA fitness standards. Legality doesn’t replace responsibility—if you’re impaired, you’re liable. Stay safe, not just legal