DMN is a supplement activated by the gut microbiome, and therefore can cause gas and bloating symptoms in some cases as your body adjusts to taking it. It is Certified Low FODMAP, meaning that it was formulated to cause less gut symptoms than other prebiotic supplements. But it is still possible, particularly among those with a damaged gut microbiome, constipation, histamine intolerance, or other food intolerances. Please review the "DMN & your health" section in our Help Center for additional insights on these conditions. Also, it is rare, but it is possible for a person to have an allergic reaction to the ingredients in DMN. We third party test for purity to insure that there are no contaminants, so that you can be confident that the only ingredients in a can of DMN are the ones seen on the package label.