It's the latter: (intentional) use of (illegal) drugs is illegal, and having THC in your blood is proof enough to convict you (even if you've consumed it in a d

It's the latter: (intentional) use of (illegal) drugs is illegal, and having THC in your blood is proof enough to convict you (even if you've consumed it in a different country where it's actually legal; there's precedent). Typically you'd just get a fine though, if you admit guilt and don't go to court. See § 1 here for the exact law: http://www.notisum.se/rnp/sls/lag/19680064.htm http://www.notisum.se/rnp/sls/lag/19680064.htm