Magnesium Ascorbyl Phosphate

Magnesium Ascorbyl Phosphate (MAP) is a water-soluble form of Vitamin C. It is used in skincare because it tends to be more formulation friendly than pure vitamin C (ascorbic acid).

According to research, MAP has three major benefits:

1. Uneven skin tone and hyperpigmentation: Lab and early clinical studies suggest MAP can help reduce excess pigmentation by slowing melanin production. This is because MAP showed signs of skin absorption when applied topically and can disrupt the key steps in melanin formation. More recent clinical trials found 5% MAP, niacinamide, and hyaluronic acid helped improved melasma (but it was less effective than hydroquinone).
2. Antioxidant support for acne and oily skin: In an in-vivo (human) study, MAP helped reduce UV-related oxidation of skin oils. Oxidized sebum can irritate the skin and trigger inflammation linked to acne. Limiting this oxidation may help calm acne-related inflammation.
3. Collagen and dermal matrix support: Older fibroblast research found MAP performed similarly to ascorbic acid in stimulating collagen synthesis and outperformed SAP.

While MAP is gentler on the skin than ascorbic acid, it is thought to be less easily absorbed into the skin.

In a well-known absorption study, pure vitamin C increased skin vitamin C levels when formulated correctly, but derivatives like MAP did not in that experiment. This suggests MAP may not always convert into active vitamin C in the skin.

Due to MAP's stability up to a pH level of 7, it is more stable to air and sunlight exposure than ascorbic acid. The best pH range for MAP is between 5 and 6.