I had headaches, but mine didn't start until the 2nd or 3rd day. It was one big, long headache really - so headache, not headaches. It lasted for a few days - I think 3-4. I seem to recall it cleared up around the end of week 1. I'd cut way back on carbs before I actually started, so I don't think it was anything to do with that. I expect it has to do with an individual's metabolism more than anything. But then, what do I know?
