I am on my 2nd day of Belviq and got a headaches so severe after the 1st dose, I've also had to start taking 800mg of Ibuprofen. This will work for about 2 hours and the headache is back with a vengeance. I've read several posts that the headaches will subside after the first couple of days, hopefully that will happen with me or I will have to discontinue usage as I can barely function at work. I've also noticed severe fatigue and chills, I almost feel like I have the flu! I'm going to stick with it for as long as I can, I hope these side effects will subside with time as it's been extremely tough on my body. More updates later on weight loss, none to date but it's only been 2 days and I've not even thought about weight loss, I'm focusing on trying to make it through the day!