IodineDoes iodine shrink a goiter or thyroid nodules?
Short answer
In children with iodine deficiency, a 2026 Cochrane review found the effect on goiter very uncertain (2 trials, 432 children).[1] Without the trial at high risk of bias, iodine likely lowered the risk of goiter by 69% (1 trial, 230 children, moderate certainty).[1] In a program in Azerbaijan with severe deficiency, goiter was found in 99% of the children examined before iodized oil and in 2% of those examined four years after. This was not a randomized trial.[2]
A German trial included 1,024 adults with thyroid nodules, in a region with enough iodine. Iodine alone for 1 year did not shrink the nodules more than placebo (a 4.0% difference, not significant). Iodine with levothyroxine, a thyroid hormone medicine, shrank them by 17.3% more than placebo.[3]
Sources (3)
- Iodine supplementation for preventing iodine deficiency disorders in children and adolescents. Velasco I, Rueda-Etxebarria M, Trak-Fellermeier MA, Taylor P, Rabassa Bonet M, Chi Y, et al. Cochrane Database Syst Rev, 2026. PMID 42720098
- Treating iodine deficiency: long-term effects of iodine repletion on growth and pubertal development in school-age children. Markou KB, Tsekouras A, Anastasiou E, Vlassopoulou B, Koukkou E, Vagenakis GA, et al. Thyroid, 2008. PMID 18399768
- Reduction of thyroid nodule volume by levothyroxine and iodine alone and in combination: a randomized, placebo-controlled trial. Grussendorf M, Reiners C, Paschke R, Wegscheider K J Clin Endocrinol Metab, 2011. PMID 21715542
More about iodine
What is iodine?Which foods contain iodine?What is iodine used for?What happens if you do not get enough iodine?Is iodine safe?Do you need an iodine supplement in pregnancy?For education; not medical advice. Talk to a doctor before you start, stop or change a supplement.