I've been taking it on and off for the last couple months. I can't say for sure that it's doing much of anything, though I do have good feelings after taking it. I believe my SIBO is a bit better too but I can't be sure it's the Prescript-Assist that's improving it. Certainly nothing bad has come from it. Ken Lassesen, who recently wrote an article praising this one, says that if a probiotic isn't causing a herx you should probably try another. So I'm moving on.