ok, i just asked my buddy that is a navy customs officer. he said that its all up to the checker himself. pretty much by what he says, if they seem to be tolerable to you bringing the supps then its a go. if he decides he needs to bring it to someone elses attention then count on losing them.
as far as losing your passport or anything else happening like a fine or anything for that matter he says that complete b.s.
unless its something of serious offense like a weapon or serious drugs he says that they will just toss them and let you go on your way.
he agreed your best bet is to check them in with your bags. just leave them in your bags and dont try carrying them on the plane since carry ons get a more detailed search. the chances of them stoping a bag thats been checked in over a bottle of supplements isnt very likely but if they pull them out in front of other people then count on a possible loss.
my source for this info is a navy customs officer and has been for 5 years. hes a very trustful friend and he use to work at dfw for 2 years.