I think in povidone, the Iodine is covalently bound to a large molecule (note to trapper, re what a molecule is) and is less available biologically from transdermal absorption then the usual Iodine supplementing person's ingestion of Lugols, Iodoral,or SSKI , etc. Yes, povidone topically gives way less Iodine to the person but at least it gives some, they might not otherwise get and I've heard andecdotes of some benefits. Of course, as you know by now Hanny, my way, is the best way. But I'm not cheap, even though I'm fast and efficacious :)