The actual effects of Kratom might be very mild compared to usual opiates (no real "high" so to speak, just a profound sense of well-being and deeply improved mood/mental clarity along with noticeably increased energy), the withdrawal symptoms SOME people experience when coming off after a heavy and extended use (15-20g several times per day non-stop for months/years) are in fact extremely close to what "addicts" of much harsher drugs feel when they have to stop... not only can't you function physically AT ALL for days straight for you're deprived of the least bit of life in you, but the psychological exhaustion/lack of motivation/unbearable anxiety you go through makes it even worse...
I learnt it the hard way, believe me.
If you've been a heavy user for quite some time and know you'll have to go somewhere where Kratom is illegal or you simply won't have access to it, plan well in advance (two months at least) the moment you'll come off... otherwise, fooling yourself into thinking you'll still be able to make it no matter what and thus stopping the day before your trip will just be a recipee for disaster.... so much that odds are high you'll have to go back home for you'll feel such a wreck one word only will define you: uselessness. And I mean it.
Everyone of course reacts differently, but be aware that THIS can happen.
Now do I think FDA should ban it? Hell no! A moderate use can and actually will dramatically improve someone's life.
But as with everything of that kind, please, guys, don't take the stuff for granted and consume it too lightly as if it was nothing... cause it's clearly not.