The ingredient, explained

Sodium Ascorbyl Phosphate

A vitamin C derivative with its own topical research, distinct from ascorbic acid.

AntioxidantTyrosinase inhibitor / brightening

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Ingredient guide

What it is and what it does

L-Ascorbic acid, 2--dihydrogen phosphate-, trisodium salt

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.

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 topical research

A randomised, double-blind acne study compared formulas with 5% sodium ascorbyl phosphate, 0.2% retinol, and their combination. Inflammatory lesion counts decreased over eight weeks, with the combination producing the largest reported reduction.

What this does not tell us

The abstract does not report sample size or describe a vehicle-only group. It does not establish preventive effects or the performance of another concentration. Results for this derivative cannot be transferred to other forms of vitamin C.

Sources for this summary. PubMed 19134126 ↗

Research review checked Sep 30, 2026

Selected primary sources were reviewed for the existing research brief on 30 September 2026, with exact ingredient, route and combination limitations recorded. This was a bounded editorial review, not a systematic search.