I about 10 day in, and I have been a little headachy and constipated too. I even took some Oxypowder just before to get things moving again. I have tried some epsom salt but that doesn't seem to have done much. I am sure it is die off. I KNOW I have parasites and I am sure that they are dying cause even with the headaches and constipation, I feel better already. I have had more energy than usual and that for me is HUGE...having suffered with CFS for many years.