big if true <| sep |> All vzw phones are unlocked <| sep |> Online TDEE calculators can be inaccurate . You are seeing this yourself . Synthroid does not cause weightloss . It is not a weightloss pill . If it takes a person out of a hypothyroid state and the person ' s TDEE is adjusted due to no longer being in a hypothyroid state and the person does not make any adjustments to intake and their intake is at a level that is lower than their TDEE , then weightloss occurs . But this is not due to the synthroid , it is due to the person no longer being hypothyroid and eating below their TDEE . You need to count calories more precisely andor lower your intake more and see if weightloss occurs over the next 46 weeks . Food scales are pretty cheap and very useful for people with hypothyroidism . When I am hypothyroid my TDEE lowers by 300 caloriesday roughly . It is enough to make me gain significant amounts of weight if I am not tracking my intake accurately with a food scale . One time I stopped tracking and gained 30 pounds in 3 months . Accurate calorie tracking and figuring out your own specific TDEE not an estimate from a website will allow you to have more control .