My husband is hypothyroid, and synthetic thyroid hormone works just fine for him. But it did nothing for me. So I guess different people will exerience different results.

I am on Armour thyroid now along with a tiny amount of Cytomel. When my thyroid is tested, I get a complete panel and the doc takes all the numbers into consideration when deciding on a dose. I feel remarkably better on dessicated than I did on the synthetics, and I have not experienced any weight gain or fluctuations in effectiveness.