Today is my first day of the Master-Cleanse as well. I posted earlier today, about having similar problems. I am surprised because I tried the Master-Cleanse last week and had no problems, but gave into food after 4 days. Stareting over now, and would love someone to go through tis with as well. I was getting a really dull headache, but drank about a quart of water and that helped. I would suggest maybe adding a little more syrup to your lemonade as the headache might be a blood Sugar thing. but YES lots of people get the headaches, especially if you are a caffine addict. It takes a couple of days to clear that out ouf your system I have heard. email me if you would like to email outside of the forum as well.