I did a flush a month ago and I didn't do the parasite cleanse. I got about 50-60 small stones and the pain in my liver/gallbladder area disappeared. I think it is effective even if you don't do a parasite cleanse first. I had to do the flush immediately because of the pain in that area, I didn't have time for the parasite cleanse. I plan to do it later, but I'm going to flush monthly for a while even without the parasite cleanse.