"been taking belviq for 3-4 weeks. side affects were mild headache,fatigue and sneezing in the 3rd week but now subsided for the most part.  i am though a little tired at the end of day and sleep well at night. i&#039;m assuming the longer you take it the more your body gets used to it. i have lost 15 lbs so far. i have cut my portions to almost half. still eating much of what i like but less. also notice  that i have made some new healthy choices. i plan to start exercising this week as well, by walking regularly until i can jog comfortably.  i know there is no perfect pill that&#039;s not going to have side affects so if there&#039;s a little discomfort in the short term for long term gains i&#039;m in. i truly belviq will help me achieve my long term goal."