I-131 Treatment  for Hyperthroidism

Radioactive iodine has been used to treat hyperthyroidism for 6 decades and is very effective if sufficient radiation i deposited in the thyroid.1 As the most preferred therapy by physicians in the US,1 the goal of administering radioactive iodine is to achieve or maintain normal thyroid hormone release from the thyroid.1

Benefits of radioactive iodine for treatment of hyperthyroidism:

  • It is a definitive cure for hyperthyroidism, unlike antithyroid  drugs, which will fail in 70-80% of patients in the U.S. after 12-18 month1
  • May help Grave’s disease patients avoid surgery and the potential side effects of antithyroid medications1
  • Most patients respond to RAI therapy with a normalization of thyroid function tests and improvement of clinical symptoms within 4–8 weeks. The success of RAI therapy in treating Grave’s disease, the most common cause of hyperthyroidism, was 86% with a 15.7 mCi dose in a randomized controlled clinical trial2
  • Most patients have normal thyroid function and no clinical symptoms within 4-8 weeks1


  1. Bahn RS, Burch HB, Cooper DS, et al. Hyperthyroidism and other causes of thyrotoxicosis: management guidelines of the American Thyroid Association and American Association of Clinical Endocrinologists. Thyroid. 2011;21(6):593–646.
  2. Ross DS, Burch H, Cooper DS, et al. 2016 American Thyroid Association Guidelines for Diagnosis and Management of Hyperthyroidism and other causes of Thyrotoxicosis. Thyroid. 2016. [Epub ahead of print]
  3. Regalbuto C, Marturano I, Condorelli A, et al. Radiometabolic treatment of hyperthyroidism with a calculated dose of 131-iodine: results of one year follow-up. J Endocrinol Invest. 2009;32(2):134-138.