Hi, my doctor just put me from 500 mg twice a day up to 3 tablets a day. The tummy upset when I first started with twice a day went away after a couple days and I was fine. When I went to add the third tablet in he told me one at breakfast, 2 at dinner. The reaction to taking 2 tablets at the same time was epic to say the least. I spent 2 1/2 days in the bathroom including all night. I have split them up and now take them three times a day with 6 hours between them and food with them and I am fine now. It might be you need to give it a few days. I have heard that every time you up the dose you have to go through that particular side effect again. Good luck