Can synthyroid make me gain weight?

Weight synthroid (thyroxine): An under active thyroid can be the cause of weight gain, lack of energy, cold intolerance, and a variety of other symptoms. An interactive thyroid is usually treated by synthroid, (thyroxine) or hormone replacement. The question might be if you are on the correct dose of the synthroid, (thyroxine) if not, one could experience weight gain, not from the synthroid, (thyroxine) but from the continued under medicated hypothyroid state.