Swanson Ultra Magnesium Oil Spray is a super-saturated spray of pure magnesium chloride and water—nothing added, nothing taken away. It’s mined from deep underground at the site of the ancient Zechstein Sea in The Netherlands. Naturopathic experts recommend magnesium oil for daily use. It’s non-greasy and absorbs rapidly leaving little residue and no unpleasant scent. Magnesium Oil consists of a supersaturated solution of magnesium chloride and pure water.