You might not be doing anything wrong. Certain prescription
medications, not all, such as those used to
treat diabetes, high blood pressure, mood disorders,
seizures and even migraines, can actually cause weight
gain – even several pounds a month. Whatever you
do, don’t stop taking the medication without speaking
with a healthcare professional first. In most cases, a
healthcare professional will be able to switch you to
another medication that helps your condition but does
not cause weight gain and, in some cases, the medication
may even help you lose a few pounds.