T3 is the active thyroid hormone. Some people do not feel their best and find it difficult to lose weight without the addition of a second thyroid hormone known as T3. (Every time you refill a generic prescription, you can get a different manufacturer's product.) Do stick with a brand name, however, and not a generic, to ensure consistency. With several FDA-approved brands (Unithroid, Lev-oxyl, and Synthroid, among others) available, you may wish to discuss a change with your physician. But some people simply do not feel well on one brand of levothyroxine, and changing brands seems to help. Most people start out taking levothyroxine. Here are some questions you can consider that address the various concerns relating to optimal thyroid function. Any of these problems can interfere with optimal thyroid function and disrupt metabolism. A number of situations can contribute to less than optimal thyroid treatment. If you are still suffering from thyroid symptoms and finding it difficult or impossible to lose weight, or you're gaining weight even though you're on a healthy diet and exercise program, there's a good chance that your thyroid treatment is not optimized. After getting diagnosed and treated, the first step is to optimize your thyroid hormone replacement treatment.

However you have gotten there, if you are battling weight issues, once you become hypothyroid, it's a shared battle. And for thyroid cancer, almost all patients have their thyroid removed entirely, leaving them completely hypothyroid and reliant on outside thyroid hormone replacement. The end result is often hypothyroidism. With thyroid nodules and goiter, surgery may be performed to remove all or part of the thyroid. Many doctors do not explain this fully to patients when they recommend RAI treatment.

With Graves' disease and hyperthyroidism, most doctors in the United States, rush to administer radioactive iodine (RAI), which leaves patients without a functional thyroid. For example, with Hashimoto's thyroiditis patients, the thyroid typically burns itself out over time, becoming less able to produce thyroid hormone, thus leaving most patients hypothyroid.