Ancient Minerals Magnesium Oil ULTRA is formulated for individuals with sensitive skin. This formula incorporates the unique benefits of OptiMSM and magnesium. OptiMSM (methysulfonylmethane) has long been revered as a superior form of sulfur supplementation. Topically, OptiMSM enhances the absorption of magnesium. Ancient Minerals Magnesium Oil ULTRA contains 63mg of magnesium and 120mg of OptiMSM per ml.