Your liver will not cleanse well if it is full of parasites. The first thing you may notice on a parasite cleanse is liver flukes and other flukes(these are a flat worm) these are the easiest to kill with the herbs, roundworms also love your liver. So that is why it is important to parasite cleanse the liver first. I have also heard that if you try to cleanse your liver without doing a parasite cleanse first you may feel quite sick because you have tried to over work your liver by cleansing it. After parasite cleansing the liver works much better and cleanses well.