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Moumoujus

PROPANEDIOL.

Valuable CAS 504-63-2 / 26264-14-2 / SOLVENT, VISCOSITY CONTROLLING

Propanediol is a multifaceted humectant and solvent, effectively enhancing skin hydration and fortifying the skin barrier. It also significantly improves the absorption and overall efficacy of other key active ingredients within a formulation, contributing to a smoother skin texture.

Summary

humectant solvent emollient preservative booster penetration enhancer viscosity reducer

Science

Mechanism of Action

Propanediol primarily functions as a humectant, drawing moisture from the surrounding environment and binding it within the skin, thereby improving hydration and strengthening the skin's natural barrier. Its robust solvent properties are crucial for dissolving challenging ingredients like salicylic and ferulic acids, facilitating their optimal absorption and biological activity. Additionally, it offers emollient benefits by softening the skin and forming a protective layer to minimize moisture loss, while also boosting preservative efficacy and reducing formulation viscosity for improved sensory characteristics.

Research

Clinical Evidence

High confidence
Effective range 5–15%
Optimal

15%

Key findings

  1. 01 Demonstrated increased skin hydration and improved skin barrier function within 15 minutes of application, with effects sustained over 2 and 8 hours.
  2. 02 Provided superior increases in hydration and barrier function, significantly reducing Trans-Epidermal Water Loss (TEWL) more effectively than lower concentrations. This effect was further amplified when combined with glycerol.

Transparency

Dusting Analysis

Not commonly dusted
Min. effective
5%

Clinical evidence shows Propanediol improves skin hydration and barrier function even at concentrations as low as 5%, suggesting genuine efficacy at low-to-moderate percentages rather than being used at sub-effective levels for marketing claims.

The Formula

Formulation

Solubility
Both
Optimal pH 4.5 – 7
0 7 14

Stability

Propanediol maintains stability under typical cosmetic conditions within a pH range of 4.5-7.0. It can also enhance overall formulation stability by decreasing the freezing point, improving performance in freeze/thaw and heated tests.

Synergies

  • Enhances the absorption and efficacy of active ingredients such as salicylic acid and ferulic acid.
  • Boosts the efficacy of preservatives.
  • Synergistic effects with glycerol at a 15% concentration for enhanced skin barrier improvement and TEWL reduction.

Conflicts

  • Can potentially lead to mild irritation if combined with an excessive number of strong active ingredients, due to its penetration-enhancing properties that may increase absorption of multiple potent compounds simultaneously.

Safety

Safety Profile

CIR Status
Safe as used
Max tested
39.9%
Sensitization risk Low

The Cosmetic Ingredient Review (CIR) Expert Panel has assessed 1,3-propanediol as safe for use in cosmetic formulations. It functions as a penetration enhancer. The highest reported concentration in cosmetic use is 39.9% in non-spray deodorants.

Your Skin

Skin Compatibility

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

Our Assessment

Verdict

Valuable

Propanediol is a valuable, well-tolerated ingredient that significantly boosts skin hydration and barrier function while enhancing the overall performance of formulations, making it a highly beneficial component in precision skincare.

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