Carry on or on you don't put that in check bag imo. Not saying to do this at all. Also depending on how much you know about the security, if it's just metal detectors you might be able to walk it thru on you in a smell proof container in a sock or something. How ever I wouldn't even attempt something like that with the new 360° scanner style detectors. Those go off randomly even when your pockets are empty. Ive also never attempted such going thru customs/international borders which would likely be much riskier both in getting caught and the repercussions.. like others are saying I'd really recommend scoring some that's already in your country. Let someone else be the mule.. also I never commented on this post if anyone asks js