Medical cannabis is legal, but roadside tests don’t distinguish between...

https://www.romeo-bookmarks.win/legal-doesn-t-mean-safe-for-ev-drivers-on-medical-cannabis-the-2mcg-l-thc

Medical cannabis is legal, but roadside tests don’t distinguish between prescription and illicit use. Stay under the 2mcg/L THC limit or rely on the medical defence. DVLA fitness standards still apply