Iodine

Which medicines interact with iodine?

Updated 10 Nov 2026

Short answer

Iodine supplements can interact with these medicines:[1]

  • antithyroid medicines such as methimazole: high doses of iodine add to their effect and can cause hypothyroidism[1]
  • ACE inhibitors for high blood pressure, such as benazepril, lisinopril and fosinopril: with potassium iodide, the potassium level in the blood can rise too high[1]
  • potassium-sparing diuretics such as spironolactone and amiloride: the same risk of high blood potassium with potassium iodide[1]

People who take these medicines regularly should discuss their iodine intake with a doctor.[1] Amiodarone, a heart rhythm medicine, and iodine contrast media used in X-ray scans are also sources of extra iodine.[2]

Sources (2)

  1. Iodine: Fact Sheet for Health Professionals. NIH Office of Dietary Supplements. ods.od.nih.gov
  2. Iodine and Hyperthyroidism: A Double-Edged Sword. Braverman KD, Pearce EN Endocr Pract, 2025. PMID 39510448

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.