i have tried a lot of minerals and vitamins and herbs and oils and... i find a lot of them wane in their efficacy after a period of time. sometimes its a day, sometimes a week or even a month but it has done all it can do. sometimes trying it again later would give more benefits but then wane again, always go away. there are just a handful of things that i take without fail - iodine, cayenne tincture, 200mcg of selenomethionine, 3-9mg of boron, and mag citrate.