For me it was about at the 2 1/2 week mark that I started seeing evidence (dead roundworm) but it was actually in the week after I stopped that I had the most significant evidence, and it lasted for about a week. Up until then I had not seen any proof of parasites, I just was desperate to feel better. I had even had a parasite stool test that came back negative. If I had waited for the results and not treated, I would have still had the parasites. I am so glad I did it. I hope you find health from your treatment!