You have to have adequate thyroid
hormone levels, from your thyroid gland
and/or from thyroid med. Although
weight gain can be related to a number of things, certainly one is low metabolism due to low thyroid levels. If you will post your thyroid related test results and reference ranges shown on your lab report, we can try to assess the adequacy of your testing and treatment. Also, what thyroid med are you taking and what dosage? What symptoms do you have other than weight gain?