I take 4, 250mg tablets four times per day and I hardly ever get headaches. I really never got them before I started the med and now I don't see myself getting them any more than I use to. Pentasa has been wonderful for me. At first, I thought it was doing nothing, but now when I look back at pictures of myself a year ago I can really see a difference in my appearance. I'm definately looking better and feeling a ton better. My co-workers have even noticed the difference. However, what works for one person is not necessarily what will work with another. Good luck with everything.