I have been using iodine on my skin periodically for over two years now. It is amazing how much the absorption time fluctuates from time to time. I don't use it regularly, but the first symptom I start actually noticing when I need more iodine is severe chilliness that isn't helped by putting on more clothes or turning the a\c up or down according to the season. There is definitely an increase in a sense of well-being and energy after the iodine is applied, plus I'm not cold anymore. I was shocked recently to find that my application disappeared in less than three hours! Needless to say, I have been diligently applying it now for a few days. I am violently allergic to iodine taken internally(rashes, swelling and, finally, hemorrhaging) but, so far, after using it on the skin for upwards of two years, no reactions whatsoever have appeared.