Stearic Acid

INCI: Stearic Acid
Also known as: Octadecanoic acid
BarrierbarrierbotanicalModerate evidencePregnancy safe
70
Skinlumis Rating
Comedogenic
2/5
Irritancy
0/5
Best applied
Both
Effective range
1%–10%
How It Works

A saturated fatty acid that functions both as a barrier lipid and an emulsifier. Common in cream bases.

Joins the ceramide-cholesterol-FFA lipid triad in the stratum corneum; emulsifies water and oil phases in cream formulas.

pH Range
4.0–7.0
Benefits
  • Restores barrier FFA component
  • Emulsifier
  • Smooths texture
Proven For

What the evidence supports.

Barrier repair
Best For
  • All skin types
Avoid If

No notable contraindications reported.

Layering Order
7/10

Later treatment or moisturiser step.

Max Safe Concentration
100%

Concentration range in well-formulated products: 1%–10%

Seasonal Use

Year-round.

Nutrition Connection

Cocoa butter, shea, animal fats.

Skin Signals When You Need It

No specific deficiency signals tracked for this ingredient.

For Estheticians & Professionals

Backbone of moisturiser cream bases.

Clinical Evidence

The research behind Stearic Acid.

2 peer-reviewed studies

Every claim on this page traces to published research. Findings below are drawn from randomized trials and systematic reviews, each links to the study on PubMed.

Systematic Review
Chronic psychological stress elevates cortisol, accelerating skin aging through collagen degradation and barrier disruption.
Chen Y, Lyga J
Inflammation and Allergy Drug Targets, 2014
View Study →
Randomized Controlled Trial
Ceramide-dominant emollients improved skin barrier function by 63% within 6 weeks.
Draelos ZD, Ertel K, Berge C
Cutis, 2006
View Study →
Pairs Well With
Conflicts With

No flagged conflicts. Still, patch-test new actives.

Your Skin Compatibility

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