The ingredient, explained

Magnesium Ascorbyl Phosphate

Selected evidence concerns human topical combination.

AntioxidantTyrosinase inhibitor / brighteningSkin conditioning

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Ingredient guide

What it is and what it does

Ascorbic acid, monoester with phosphoric acid, magnesium salt -2:3-

About this ingredient: EU CosIng ingredient registry (via Open Beauty Facts taxonomy) ↗

Antioxidant: Limits oxidation, including deterioration of formulation ingredients. This label alone does not show a clinical antioxidant effect in skin.
Tyrosinase inhibitor / brightening: Research category for changes in pigmentation or uneven skin tone. The label does not establish that a finished product changes pigmentation.
Skin conditioning: A broad cosmetic role for maintaining skin condition. It does not identify a particular clinical benefit.

Function definitions: European Commission ingredient function definitions (SCCNFP/0299/00, pages 16 to 20) ↗ · Original niacinamide study: Pigmentation and hyperpigmented spots ↗

Registry functions describe possible formulation roles, not results for a finished product. A dictionary entry is not an approval or a safety assessment.

A closer look

What the research shows

Human research on a combination

Adding MAP increased the proportion of patients meeting the study threshold for melasma-score reduction compared with TCA alone.

What this does not tell us

Adjunct to TCA peeling, with tretinoin priming and sun protection. No isolated MAP-versus-vehicle comparison.

Sources for this summary. PubMed 27504543 ↗

Research review checked Oct 1, 2026

Bounded review of 4 local candidate titles, selected relevant local abstracts, and targeted primary-source web searches. Not an exhaustive systematic review.