Magnesium Ascorbyl Phosphate

Magnesium ascorbyl phosphate (MAP, for short) is a water-soluble form of vitamin C made by combining ascorbic acid (pure vitamin C) with a magnesium salt to improve its stability in water-based formulas. It is considered stable in the presence of light and air but is not impervious to diminished efficacy when exposure to both elements is persistent. Unlike other water-soluble forms of vitamin C, magnesium ascorbyl phosphate is also lipophilic, or oil-loving, which improves penetration into skin (although how well this form converts to ascorbic acid within skin is up for debate). Because of its oil-loving nature and its ability to promote hydration deeper in skin when compared to ascorbic acid (which instead showed greater antioxidant ability), MAP is considered one of the most hydrating forms of vitamin C. Like most forms of vitamin C, magnesium ascorbyl phosphate has been shown to improve the look of an uneven skin tone when used in concentrations between 2-5%. Concentrations between 5-10% are known to have more pronounced benefits for discolourations, including post-breakout marks, as well as improving skin’s firm look and feel. Amounts below 2% all the way down to 0.1% still deliver antioxidant benefits. Magnesium ascorbyl phosphate does not require the same low pH ascorbic acid does in order to be effective. It works best at pH levels between 5-6. Going above pH 6 can cause this ingredient to discolor. This form of vitamin C may play a special role in reducing the likelihood of blemishes since its soothing action helps quell an of oil-based saccharide that can irritate skin. However, research on this matter was not comparative, meaning we don’t know how a range of other forms of vitamin C would’ve fared. It is considered safe as used in cosmetics.