Iodine is likely safe for most individuals when used in daily recommended doses. The most common side effects of iodine when taken by mouth include nausea, stomach discomfort, runny nose, headache, metallic taste, and diarrhea. Iodine may also cause an allergic reaction with symptoms such as a rash, hives, swelling of the throat, joint pain, or fever.
Iodine may be unsafe at high doses (i.e., above the daily upper tolerable limit) or with chronic use. At high doses, iodine may cause sore teeth and gums, burning in the mouth and throat, throat inflammation, wasting, swollen glands, diarrhea, loss of appetite, and depression. Thyroid function can be affected when iodine is used continuously over the long-term.
When come in contact with skin, iodine may cause skin irritation and stains. Bandages should not be used to cover iodine-treated areas to avoid iodine burn.
Iodine should be used with caution if you have the following conditions:
- animal bites
- deep puncture wounds
- gastrointestinal disorders
- heart problems
- kidney problems
Iodine can interact with the following medications:
- ACE inhibitors (e.g., captopril, enalapril, ramipril)
- angiotensin receptor blockers (e.g., candesartan, irbesartan, valsartan)
- anticoagulants (e.g., heparin, warfarin)
- antithyroid medications (e.g., methimazole, propylthiouracil)
- medications or herbs that contain high iodine levels (e.g., amiodarone, bladderwrack, kelp, seaweed)
- medications that increase or decrease thyroid levels
- potassium-sparing diureticdiuretican agent that increases urine flows (e.g., spironolactone, amiloride)
You should see your doctor before taking iodine if you are pregnant or breast-feeding or if you have a thyroid condition, as the daily iodine requirements may change during these periods. Do not take iodine if you have a known allergy to iodine or iodide products.
Before taking any new medications, including natural health products, speak to your physician, pharmacist or other healthcare provider. Tell your health care practitioner about any natural health products you may be taking.