"belviq works great for an appetite suppressant.  i experienced a little dizziness and a couple first days i had slight chills. (? - could be coincidental)  but 2 times i took it with allegra-d and had a horrible headache - the kind where you think you might puke...migraine status.  i truly believe it was just the combination of the pseudoephedrine and the belviq.  i&#039;ve never had a headache when i take it with benadryl. (i have bad spring allergies)"