On 200mcg levothyroxine tsh is .4 still gaining lots of weight, very tired all the time.?

Not thyroid.: If your TSH is 0.4 you are on the right dose of levothyroxine. Continued weight gain and tiredness are likely due to something else. Some physicians might measure your free T3 (liothyronine) / free T4 and consider boosting your dose or supplementing you, but i think you have another issue. Regular exercise, sleep and a good diet.