Dr. Clark's book highly recommends that you do the parasite and kidney cleanse before the liver cleanse. I was only able to complete the parasite cleanse and am on a maint. dose every week. I have always been very sensitive to meds and vitamins and have severe food allergies so I was not able to take all the ingredients in the kidney cleanse. But I finally got up the courage to go ahead with the liver cleanse and have had success. It hasn't made me sick which is what Dr. Clark says could happen if you don't cleanse for parasites and kidneys. I don't know what would happen if you did't do the parasite cleanse since I was able to complete that.