If you're flying from a 1st world airport forget about hiding drugs on or in you. If you aren't clever enough to figure out a way to duck the detection systems on your own then you don't have a chance in hell to evade them. That's not to be disparaging to you, it's just that these security checks are very invasive and designed to catch "clever" people. Please do not swallow a lethal amount of heroin
Better option, research the area you're going to and see if kratom is legal there and put up with some withdrawals.
But either way this kind of stuff is against the rules, sorry