I have used this product off and on for a few years. I certainly have seen the benefits in my skin, nails and hair. This brand/type was recommended by my doctor. That being said, it absolutely caused my Reflux to be worse and that was only with 2 scoops a day. At one point, before I connected the dots, I tried taking it twice a day and had many other digestive issues. I don't think it is just this product, I think all Collagen can cause this if a person is sensitive to such side effects. Perhaps it was just my body's reaction to it