"Is Iodine from kelp and ammonium Iodide in glycerin. It has been used since 1945. I don’t know any more about it than that. some people feel iosol functions better in the body because they believe that potassium Iodide congests the thyroid. Everything I have read indicates that potassium Iodide is the preferred form for the thyroid. The studies that suggest it congests the thyroid are the same flawed studies that suggest that too much Iodine causes Hashimoto’s thyroiditis which has already been disproven. Being glycerin based I would think Iosol would be a good alternative for use on the skin in sensitive areas.