Epsom salt (magnesium sulfate) added to a bath can raise magnesium levels in the body, according to a preliminary study. Details, including the amount of Epsom salt needed, are found in the Epsom salt section of the Magnesium Supplements Review. Also see the evidence regarding other transdermal methods of obtaining magnesium (e.g., creams, sprays and oils) and our Top Picks among magnesium supplements.
Be aware that it can be dangerous to ingest large amounts of Epsom salt. Learn more about this and other Concerns and Cautions with magnesium supplementation.