The ingredient, explained

Melatonin

Melatonin has been studied topically in experimental UV exposure. These studies do not concern sleep treatment.

Antioxidant

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Ingredient guide

What it is and what it does

N--2--5-Methoxyindol-3-yl-ethyl-acetamide

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.

Function definitions: European Commission ingredient function definitions (SCCNFP/0299/00, pages 16 to 20) ↗

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, blinded human study applied melatonin, ascorbic acid and alpha-tocopherol, alone or in combinations, 30 minutes before UV exposure. Melatonin showed a dose-related reduction in erythema, with stronger responses in the antioxidant combinations.

What this does not tell us

The abstract does not report sample size or concentrations. Short-term redness after experimental irradiation does not establish a sunscreen rating, protection against skin cancer or long-term cosmetic benefits.

Sources for this summary. PubMed 9767255 ↗

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.