I found an anti-dandruff shampoo in France that was marvelously effective but whose active ingredient isn't in any US anti-dandruff shampoos. I brought four bot

I found an anti-dandruff shampoo in France that was marvelously effective but whose active ingredient isn't in any US anti-dandruff shampoos. I brought four bottles back. I don't need to use it very often to get the effect, shipping liquids is expensive, and I had spare room in my luggage. OTOH, nobody is trying to smuggle cocaine from France to the US.