Epsom salts is the common name for magnesium sulfate heptahydrate, sometimes called bitter salts. Salts are molecules that form because the parts have opposite electrical charges that bind together. Magnesium has a positive charge; sulfate has a negative charge. The magnesium and sulfate in the salts are absorbed into the body through the skin. Any Epsom salts left on the skin may continue to be absorbed as long as it is still on the skin (up to nine hours), offering continuous “timed-released” input into the bloodstream. Epsom salts comes in crystal, gel and liquid forms, and has been used since the 1600s for a multitude of non-medicinal purposes as well as some very familiar medicinal uses including calming salt baths, easing achy muscles, compresses for insect bites, migraines, laxative, purgative, and “the ultimate foot soak.” It can be inexpensively purchased at most local grocers, drugstores, or health food stores.