I've had no problem with carry-on Clear Care travel bottles in the ziplock bag so far - didn't know others had problems with it. Maybe I'm just lucky. I guess they may not like the hydrogen peroxide. I would hate to have TSA give me trouble about it though especially since it's not available in many countries (everywhere but the US I've been to seems to only have the vastly inferior predecessor, AO Sept). Either that or just check it in, I guess, even though I'm loathe to do that.