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Moumoujus

ISOSTEARIC ACID.

Valuable CAS 30399-84-9 / 2724-58-5 / BINDING, CLEANSING, SURFACTANT - CLEANSING, SURFACTANT - EMULSIFYING

Isostearic Acid is a versatile fatty acid that significantly enhances skin hydration by forming a protective surface barrier. It functions as a non-greasy emollient, promoting skin smoothness and elasticity, while also optimizing the absorption of other active ingredients and stabilizing cosmetic formulations.

Summary

Emollient Moisture Barrier Support Antioxidant Anti-inflammatory Emulsifier Binding Agent Cleansing Agent Surfactant

Science

Mechanism of Action

On the skin's surface, Isostearic Acid creates a protective occlusive layer that effectively minimizes trans-epidermal water loss, thereby locking in moisture and maintaining optimal hydration. This action robustly supports the skin's natural barrier function against environmental aggressors. Beyond its emollient properties, it exhibits antioxidant activity by neutralizing free radicals, which contributes to the mitigation of visible aging signs, and also possesses anti-inflammatory benefits. In cosmetic formulations, it performs several roles, including emulsifier to stabilize oil and water phases, binder for solid formulations, cleansing agent, and surfactant.

Research

Clinical Evidence

Low confidence
Effective range N/A
Optimal

N/A

Transparency

Dusting Analysis

Not commonly dusted

The Formula

Formulation

Solubility
Oil
Optimal pH 4.5 – 7
0 7 14

Stability

Isostearic Acid's unique branched molecular structure provides excellent thermal, odor, and oxidation stability, which extends product shelf-life. This structure enhances fluidity, prevents crystallization at lower temperatures, and aids in stabilizing pigments and mineral particles. It is compatible with both oil-based and water-based formulations and helps to stabilize emulsions.

Conflicts

  • Vitamin C
  • Retinoids

Safety

Safety Profile

CIR Status
Safe as used
Max tested
undiluted%
Sensitization risk Low

The CIR Expert Panel concluded Isostearic Acid is safe for use in cosmetics, a finding reaffirmed in 2002. Clinical studies demonstrated no irritation, sensitization, or phototoxicity, even when applied undiluted. While some data suggested a potential for comedone formation, the CIR Expert Panel deemed the available tests insufficient to definitively predict human comedogenicity. When derived from plants, Isostearic Acid adheres to EU Cosmetics Regulation for products marketed in Europe.

Your Skin

Skin Compatibility

Yes Normal
Yes Dry
Yes Oily
Yes Sensitive
Irritancy Low
Comedogenicity Low

Our Assessment

Verdict

Valuable

Isostearic Acid is a valuable ingredient, offering comprehensive benefits for skin hydration, barrier integrity, and formulation stability with a low irritancy and comedogenicity risk profile across all skin types.

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