The way I understand it is that because it can be used to make meth, various federal and state laws have been passed in the U.S. restricting how much of an OTC medication containing pseudoephedrine can be purchased at a time and how you have to go about acquiring it; I know that in my state, they have to keep them behind the counter and collect personal information if you try to actually buy them. And of course, no company is particularly excited about their products now being so much more difficult to sell, so they are generally reformulating them with alternative decongestants, which allegedly work for other people but for me, not so much.