Magnesium Ascorbyl Phosphate is a stable, water soluble derivative of Vitamin C (L-Ascorbic acid mono-dihydrogen phosphate magnesium salt). Unlike L-Ascorbic Acid, it does not readily degrade in formulas containing water.  It is considered light-stable and oxygen-stable. Studies of MAP in aqueous solutions indicate it retains over 95% of its potency at 40°C without any pH adjustment. According to SmartSkincare.com, Magnesium Ascorbyl Phosphate …