Ingredients

Magnesium Ascorbyl Phosphate

Written by Reviewed by the SYNC editorial team Published Last reviewed Editorial standards

Magnesium Ascorbyl Phosphate — a stable, water-soluble magnesium salt of vitamin C that converts to ascorbic acid in the skin, offering antioxidant protection and support for a brighter, more even complexion. It is milder than pure vitamin C and often selected for dry or sensitive skin types.

Key points

  • Magnesium ascorbyl phosphate (MAP) remains stable at a more neutral pH than L-ascorbic acid.
  • It is studied for its ability to support collagen and help reduce the look of uneven tone.
  • MAP is considered gentle and is less likely to cause stinging or irritation than the pure acid form.
  • It also has hydrating qualities, which can make it well suited to drier skin.

Frequently asked

What is the difference between magnesium and sodium ascorbyl phosphate?

Both are stable vitamin C salts, but magnesium ascorbyl phosphate is often favored for dry or sensitive skin, while sodium ascorbyl phosphate is frequently used in oil-prone formulas.

Can magnesium ascorbyl phosphate be layered with other actives?

It generally layers well with hydrating ingredients and niacinamide, though it is best to introduce new actives gradually and monitor how your skin responds.

Related topics

This is a foundational entry in the SYNC Skin Encyclopedia and is expanded over time. Educational information only — not medical advice.

Encyclopedia

Further reading

This entry was written and checked against the sources below. They are published by clinical and scientific bodies, they are listed most readable first, and each one opens in a new tab. They are background for the whole entry rather than footnotes to individual sentences.

  1. Ascorbic Acid (Vitamin C) as a Cosmeceutical to Increase Dermal Collagen for Skin Antiaging Purposes PubMed Central Peer-reviewed, open access pmc.ncbi.nlm.nih.gov
  2. Topical Vitamin C and the Skin: Mechanisms of Action PubMed Central Peer-reviewed, open access pmc.ncbi.nlm.nih.gov
  3. Vitamin C in dermatology PubMed Central Peer-reviewed, open access pmc.ncbi.nlm.nih.gov
  4. A review of topical vitamin C derivatives and their efficacy PubMed Peer-reviewed (abstract) pubmed.ncbi.nlm.nih.gov
  5. Vitamin C NIH Office of Dietary Supplements Clinical guidance ods.od.nih.gov
  6. Vitamin C cream DermNet NZ Clinical guidance dermnetnz.org

SYNC does not publish medical advice. Nothing here replaces a consultation with a doctor or a pharmacist about your own skin.