Science
Mechanism of Action
1,2-Hexanediol operates as a humectant by drawing moisture from the environment and deeper skin layers, forming a protective barrier that reduces evaporation and promotes a plump, hydrated appearance. As an emollient, it contributes to softer, more refined skin texture. It serves as an effective solvent, dissolving and uniformly dispersing various ingredients like vitamins and botanical extracts, thereby optimizing their efficacy and even delivery. Crucially, it acts as a preservative enhancer and antimicrobial agent, inhibiting bacterial, fungal, and microbial growth to extend product shelf life and allow for reduced concentrations of other preservatives. Additionally, it boosts the penetration of active molecules into the skin and refines emulsion particle size for smoother, more readily absorbed formulas.
Research
Clinical Evidence
High confidenceN/A
Key findings
- 01 Demonstrates significant enhancement of skin hydration.
- 02 Effectively controls bacterial, fungal, and microbial growth, meeting Challenge Test standards (EP level A) against five germ types. Also functions as a preservative booster, allowing for at least a 50% reduction in other preservatives, while increasing sun protection efficiency and reducing emulsion particle size.
- 03 Recommended as a penetration enhancer to facilitate deeper delivery of various ingredients into the skin.
- 04 Recommended for its water-binding (humectant) effect and for boosting sun protection efficiency in sunscreen formulas.
- 05 Exhibits a clear anti-corrosion (preservative) effect.
- 06 Caused no skin irritation in human trials on 224 subjects (in carbomer gel) or 101 participants (in a semi-closed patch test).
- 07 Showed no delayed Type IV hypersensitivity reactions in a 48-hour repeat insult patch test on 205 participants (in carbomer gel).
Transparency
Dusting Analysis
The Formula
Formulation
Stability
Freely soluble and miscible in water, hexanediol is easily incorporated into diverse formulations. It significantly boosts the preservative efficacy of products, thereby extending their shelf life by inhibiting microbial growth. It also contributes to emulsion stability and aids in the solubilization of other active ingredients.
Synergies
- Other preservatives (boosts antimicrobial properties)
- Active ingredients (enhances penetration and dispersion)
- UV filters (increases sun protection efficiency)
Conflicts
- Methicone
- Glycolic Acid
- Kojic Acid
- Alpha Arbutin
Safety
Safety Profile
The Cosmetic Ingredient Review (CIR) Expert Panel has determined 1,2-Hexanediol to be safe under current usage practices and concentrations. The EPA Safer Chemical program classifies it as a 'low concern.' While generally considered mild, some individuals, especially those with sensitive skin, may experience irritation or allergic reactions, with reports of severe irritation around the eyes. A patch test is recommended before full application for sensitive skin types. For children's products, the EU's allowed value is 4%. It has a comedogenic rating of 0, indicating it is non-comedogenic and suitable for acne-prone skin.
Your Skin
Skin Compatibility
Our Assessment
Verdict
Hexanediol is a valuable, multifunctional ingredient that profoundly enhances skin hydration, product stability, and the efficacy of other actives through its potent humectant, preservative-boosting, and penetration-enhancing properties.
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References
Sources