Epsom salt may be more appropriate for soaking, as the magnesium diffuses into the bloodstream more slowly, however heed to the warning labels on the bag. If you use Epsom internally as a supplement for magnesium you want to avoid giving yourself a potassium deficiency, and that goes with any magnesium supplement, but is especially important for those on a diet low in potassium, or have low blood potassium levels. Diarrhea is a sign you have taking too much, unless you're intentionally trying to use it as a laxative. I would include grapefruit and oranges in my diet especially if using Epsom, and would not use Epsom internally long periods; have a blood test done, or watch out for signs of potassium deficiency if you're a chronic Epsom user. I read that magnesium taurate was once said to be the best form of magnesium, citrate being next, especially for those with mineral imbalances and prone to heartbeat irregularities.