Hello Jill, I started about a month ago on Phen and my first couple days I was cleaning my office moving things around. I'm sure my co-workers thought I was on crack.. LOL. But that didn't last for long everything is ok now. I've had a couple headaches. I would recommend to you to take only half of you pill when you start. I know a lot of people do that first cause they felt the same way. GOOD LUCK!!