Treatment for Underactive Thyroid

Whether an underactive thyroid is treated will depend on if a person is experiencing symptoms and, if so, how severe they are. Medications are used to return thyroid levels to normal, which is determined using a blood test. Called thyroid hormone replacement therapy, this treatment plan is individualized for each person -- there is no "one-size-fits-all" dose, nor is there one medication that is right for every person.

How Is an Underactive Thyroid Treated?

The goals of treatment for an underactive thyroid are to return levels of TSH and T4 to normal levels and to improve symptoms caused by low thyroid hormone levels. This is done with thyroid hormone replacement therapy.

Using Medicine to Treat an Underactive Thyroid

Thyroid hormone replacement therapy uses synthetic thyroxine to return thyroid hormone levels to normal. Synthetic thyroxine is identical to the T4 made by the thyroid. Brand-name versions of this medicine include Levoxyl®, Synthroid®, Levothroid®, Tirosint®, and Unithroid®. Levothyroxine is the generic version.
Taking either the brand-name or generic version of these medicines for underactive thyroid treatment is fine. But once you start a specific medicine, it is best that you not switch between brand-name and/or different generic formulations (see Generic Levothyroxine for more information on why this is the case).
Thyroid hormone replacement therapy is not a "one-size-fits-all" medication, and there is no "standard" dosage. People have varying degrees of hypothyroidism and, as a result, their dose must be individualized.
Healthcare providers test TSH levels about six to eight weeks after a person begins treatment for an underactive thyroid and make any necessary adjustments to the dose. Each time the dose is adjusted, the blood is tested again. Once a stable dosage is reached, blood tests are normally repeated in six months and then once a year after that.
Never adjust your dose without talking to your healthcare provider first. Taking too much thyroid medicine can cause hyperthyroidism (too much thyroid hormone) and can increase the risk for certain medical conditions, including atrial fibrillation and osteoporosis.
(Click any of the links above to learn more about the specific medicine you may already be taking.)
Last reviewed by: Arthur Schoenstadt, MD
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