The ingredient, explained

Malic Acid

Selected evidence concerns human topical irritation experiment.

AHA exfoliantBuffering

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Ingredient guide

What it is and what it does

Butenedioic acid, hydroxy-, -2S--

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

AHA exfoliant: Alpha hydroxy acid category. Exfoliation depends on the acid, concentration, pH and the rest of the formula; an AHA may also be used to control pH.
Buffering: Helps resist changes in a formula's pH.

Function definitions: FDA: Alpha hydroxy acids ↗ · 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

Malic acid alone did not significantly irritate skin under the tested conditions, and fruit-acid/SLS exposure did not increase cumulative irritation compared with SLS/water.

What this does not tell us

Four-day experimental exposure in healthy volunteers, not a full cosmetic safety assessment, exfoliation trial or guarantee of tolerability at other concentrations. Sample size absent from abstract.

Sources for this summary. PubMed 16040403 ↗

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.