I completely understand what you're saying and I'm sure there are plenty of people who just take it and wait for the weight loss. I am on a combo of T3 and Synthroid and I have adjusted till my levels all evened out in labs. I am at my ideal dose now. Still gaining, though I am reading a ton of info on fluid retention and may try to focus on that. I have read contless stories of health nuts on Syntroid who work out, do Yoga etc, and can't lose weight. I wonder..
The thing is, it is not the medication causing the weight issue, rather it is the fact the dose you take is not correct for your brain and thyroid to work together to keep you at a healthy weight.
Having said that, if you expect the Synthroid to be a weight loss product and you continue to eat big time, of course it won't work.
Thyroid medications can be very tricky for each individual to get the right dosage.
Let me explain...Pretend you are taking 100mcgs of Synthroid and your brain is sending out a message to the thyroid to make more thyroid hormone, and your thyroid says, Meh....I done my job. Then the brain sees that the thyroid is being a bit slack and says, OY! Get with it! ...thyroid says...yeah yeah whatever.....Thyroid just keeps on going into sleep mode and your body slows down...the weight starts increasing...After some time, you as the patient think..Holy cow, this medication is the pits... I need something better....STOP RIGHT THERE! It is NOT the medication but the dosage. You might need more to make the brain and thyroid start to understand that you are trying to help.
So you go up a dose, say to 125mcgs. You wait a while and you see it is starting to be ok. For some it might be a higher dose. But always remember, good eating, some moderate exercise is always going to help. Just don't presume the Synthroid is the 'cure all' It just ain't like that.
Cheers