I have taken DPP IV tablets for a while. (from Kirkman Labs) I have tried them on my son and seen improvements - but removing gluten and dairy totally from his diet works far, far better. Getting the right dose is very hit and miss. They definitely help clear up brain fog if you have eaten some gluten or dairy. I often get a headache with them though, and I cannot figure out if this is because I not getting the right dosase to deal with the amount of gluten, or if they start attacking some intestinal biofilm and trigger a herx reaction. I need more time to experiment, but I think there are other factors going on and this is only one of them. If anyone else has tried the tablets I'd like to hear how you got on.