Sometimes yes - just keep the water intake at 2 quarts or more to keep the toxins flushing. Also make sure your bowels are working properly - totally eliminating waste will help. I don't want to scare you off of your cleanse, but sometimes when the parasites are removed, the body is better able to utilize the foods that are consumed - so sometimes underweight people gain weight. This is probably not your case, but I just wanted you to be aware of it.