Zechstein Magnesium Oil is a saturated magnesium chloride solution that is applied to the skin. The solution is referred to as magnesium oil because it feels oily, although it is not oil in the traditional sense. The former Zechstein Sea dried up about 250 million years ago, and the minerals contained within it have settled and are now located about 1600 meters deep in the Earth. Zechstein Magnesium Oil classic is sprayed directly onto the affected areas and massaged in. The application can be repeated as needed. Zechstein Magnesium Oil can also be applied and massaged in preventively for recurring nighttime calf cramps.