Butylene glycol is a humectant—a type of ingredient that draws water into the skin and helps it stay hydrated. It's a small, lightweight molecule commonly used in moisturizers to improve hydration without leaving a heavy feel on the skin.
Benefits
Increases skin hydration and moisture retention
Lightweight and absorbs quickly
Helps other active ingredients penetrate the skin more effectively
Science: Research demonstrates that butylene glycol, when combined with other humectants (like glycerin and hyaluronic acid) and occlusive ingredients in moisturizers, significantly improves skin hydration in both healthy skin and compromised skin conditions such as atopic dermatitis. It is recognized as a safe, effective humectant in dermatological formulations.
2-Hexanediol is a humectant and preservative booster commonly used in skincare products to help retain moisture and extend shelf life. It works by drawing water into the skin while also enhancing the effectiveness of other preservatives, allowing brands to use lower amounts of traditional preservatives.
Benefits
Hydrates and moisturizes skin by drawing in water
Helps preserve products with lower preservative levels
Works synergistically with other skincare ingredients like niacinamide
Potential concerns
May cause cell viability concerns at concentrations above 1.0% in laboratory studies
Limited real-world safety data in humans at typical skincare concentrations (usually 2-5%)
Potential environmental concern if released into water systems
Science: While 2-hexanediol is widely used as a preservative substitute for parabens, recent cytotoxicity studies raise questions about safety at concentrations commonly found in skincare products (>2%). However, these findings are from laboratory cell studies and may not directly translate to human skin application. Further human safety studies are needed to confirm real-world risk.
