I have carried on the airplane many times without incident. I usually just put it in a film canister and stick in my toilet bag... if you are worried, there are some toothpaste dispensers which are a plastic casing, the bottom can be easily removed and you can stuff a couple grams up there. It would take a persistent dog for them to rip open your toothpaste, but I have NEVER, EVER seen a sniffing dog in the airport... I fly about 4-5 times a year, in the U.S. and International. Good Luck... remember the movie "Midnight Express"?