Get a Free 5ml Mini Now Free 5ml Mini With Every Order of The Mantle
Moumoujus

PROPYLENE GLYCOL.

Valuable CAS 57-55-6 / HUMECTANT, SKIN CONDITIONING, SOLVENT, VISCOSITY CONTROLLING

Propylene Glycol is a highly versatile ingredient, primarily valued as a potent humectant that draws moisture into the skin to enhance hydration. It also acts as an effective solvent, facilitating the even distribution and improved penetration of other active ingredients, while contributing to overall product stability.

Summary

Moisturizer/Humectant Solvent Skin Conditioning Viscosity Controlling Penetration Enhancer Antimicrobial

Science

Mechanism of Action

Propylene Glycol functions as a humectant by attracting and absorbing water from the environment into the outer layer of the skin, thereby alleviating dryness and flakiness. It serves as a solvent, dissolving active components and acting as a carrier to ensure uniform distribution and enhanced dermal absorption. Additionally, it offers emollient properties, filling gaps between skin cells to form a protective barrier that reduces transepidermal water loss, and exhibits antimicrobial attributes that bolster preservative efficacy and product longevity.

Research

Clinical Evidence

High confidence
Effective range N/A
Optimal

For optimal humectant benefits with a generally safe profile, concentrations below 5% are frequently utilized.

Key findings

  1. 01 At low levels, typically below 5%, Propylene Glycol effectively acts as a humectant, improving skin hydration and is widely considered safe for most users.
  2. 02 Concentrations ranging from 10-25% may function as penetration enhancers, yet levels exceeding 10% have been linked to potential skin irritation in some individuals.
  3. 03 Clinical observations report that even 2% Propylene Glycol can be associated with irritation and contact dermatitis in susceptible individuals, with higher concentrations (e.g., 20%, 100%) potentially inducing eczematous skin reactions in patch tests.

Transparency

Dusting Analysis

Not commonly dusted
Red flag below
10%

While efficacious as a humectant at low concentrations, Propylene Glycol's role as a penetration enhancer can prompt the use of higher percentages. Concentrations above 10% significantly increase the risk of skin irritation and sensitivity, underscoring the necessity for careful formulation to balance desired effects with dermal tolerance.

The Formula

Formulation

Solubility
Water
Optimal pH 9.3 – 10.5
0 7 14

Stability

Propylene Glycol demonstrates high stability due to its low volatility and high boiling point (188.2 °C), contributing to product shelf life and improving freeze-thaw stability. However, it can degrade when exposed to high temperatures. Concentrations at or above 20% also contribute to biological integrity by inhibiting the growth of most microbes and fungi.

Synergies

  • Enhances the efficacy of preservative systems.

Conflicts

  • Oxidizing reagents (e.g., potassium permanganate).

Safety

Safety Profile

CIR Status
Safe as used
Max tested
98%
Sensitization risk Moderate

The Cosmetic Ingredient Review (CIR) Expert Panel concluded Propylene Glycol is safe for cosmetic use when formulated to be non-irritating, even approving concentrations up to 98%. The FDA classifies it as 'Generally Recognized as Safe' (GRAS). Despite a generally favorable safety profile, some individuals may experience contact dermatitis or irritation, particularly at higher concentrations or due to individual sensitivities.

Your Skin

Skin Compatibility

Yes Normal
Yes Dry
Yes Oily
No Sensitive
Irritancy Low
Comedogenicity Low

Our Assessment

Verdict

Valuable

Propylene Glycol is a valuable, multifunctional ingredient offering significant hydration, enhanced ingredient delivery, and crucial formulation stability, recognized as safe when expertly utilized within appropriate, non-irritating concentrations.

Related

Similar Ingredients

Finding similar ingredients…