Is Potassium Iodide (SSKI/KI) Safe with Iodine?
Free · No account · based on published sources including NIH ODS, FDA drug labels, and peer-reviewed literature
Avoid combining dietary iodine supplements with potassium iodide preparations unless medically directed (e.g., radiation emergency). Excess iodine intake can paradoxically block thyroid hormone synthesis and cause hypothyroidism, particularly in individuals with underlying thyroid autoimmunity.
Why this interaction occurs
The Wolff-Chaikoff effect describes acute inhibition of thyroid hormone synthesis when iodine intake suddenly increases dramatically. Individuals with Hashimoto's thyroiditis or previous thyroid surgery are unable to escape this effect normally, making them highly susceptible to iodine-induced hypothyroidism when high-dose iodine supplements are layered upon dietary sources or potassium iodide preparations.
Evidence
Evidence level: strong.
Reported safety data
The FDA’s adverse event reporting system (FAERS) has received 7,125 reports mentioning Iodine. This reflects reported cases involving the medication in general — not confirmed causation, and not specific to the Iodine + supplement combination on this page.
FAERS reports are voluntary and cannot prove that a drug caused an event. Do not use report counts to assess the safety of this specific drug-supplement pair.
Frequently asked questions
Related interactions
All Potassium Iodide (SSKI/KI) interactions → · All Iodine interactions →
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Educational only — not medical advice.
Always confirm with your doctor or pharmacist.