Yes, some get occasional headaches while in the beginning stages of Medifast. They are generally due to your body getting used to doing without! Without is from all the sugar and calories and extra junk (for lack of a better word) you’re used to taking on a daily basis. Medifast cuts this to almost zero, and it takes awhile for your body to get used to it. Does not take long, you will actually feel better than normal after only a short while.
Gander here:
http://www.makemethinner.com/forum/diet-566.html
This is the FAQ section, and search (CNTL-F) for headaches, there are a few items listed, and what you can take.
-Mike