Medications used for the preventive treatment of migraine headaches can cause weight loss, but more often cause weight gain.  An interesting study by Dr. Bigal and his colleagues, just published in Cephalalgia looked at this effect of drugs in 331 patients.  They found that 16% of them gained weight (5% or more of their baseline weight) and 17% lost weight.  The various treatments given to these patients were equally effective in both groups.  However, not surprisingly, those who gained weight had elevation of their cholesterol, blood glucose, blood pressure and pulse.  Patients who have migraine headaches with aura (about 15-20% of migraine sufferers) already have an increased risk of strokes, so adding additional risk factors for both strokes and heart attacks should be especially avoided in this group.  The only preventive migraine drug which consistently lowers weight in many patients is topiramate (Topamax).  This drug is now available in a generic form, making it much less expensive.  While topiramate does lower weight and helps prevent migraine headaches only half of the patients stay on it.  For the other half it causes unpleasant side effects (memory impairment and other) or it does not work.