Stomach irritation is very common and for me it usually happens on an empty stomach or when I am very dehydrated. If you are taking some strong stacks, for example your Lipo 6 & ephedrine hcl, you are probally going to suffer from this more often than others taking a pure ECA stack. When you think about it..your taking yohimbrine hcl, synephrine hcl, ephedrine hcl, and caffeine along with some of the smaller ingredients so its to be expected.

I wouldn't worry too much about it but your best bet to avoid it is to take the stack somewhere around meal time or at least not on an empty stomach and to drink plenty of fluids.