Glycerin
The original humectant — a simple, effective molecule that draws moisture to the skin and keeps it there, forming the backbone of hydration.
What Is Glycerin?
Glycerin (also called glycerol) is a colorless, odorless, viscous liquid that is arguably the most foundational hydrating ingredient in all of skincare. It's a trihydroxy alcohol that functions as a humectant, attracting water from the environment and from deeper skin layers to the stratum corneum. Glycerin is a component of the skin's natural moisturizing factor (NMF) and plays a critical role in maintaining skin hydration, elasticity, and barrier function. Research has shown that glycerin doesn't just passively attract water — it actively facilitates water channel (aquaporin-3) function in skin cells, improving the skin's own ability to transport and retain moisture. Despite being one of the oldest and least expensive skincare ingredients, glycerin remains unmatched in its combination of efficacy, safety, and compatibility.
Key Benefits
- Provides reliable, long-lasting hydration as a powerful humectant
- Strengthens the skin barrier and improves elasticity
- Enhances the skin's natural water transport (aquaporin function)
- Protects against irritation and environmental damage
- Improves the texture and spread of skincare formulations
- Compatible with virtually every other skincare ingredient
How to Use Glycerin
Glycerin is a workhorse ingredient found in most moisturizers, serums, and toners — you're likely already using it without realizing. In standalone glycerin products, apply to damp skin after cleansing and follow with an occlusive or emollient to seal in the moisture. Pure glycerin should always be diluted (never apply 100% glycerin to the skin, as it can draw moisture out in dry conditions). Typical skincare concentrations range from 3–20%. Can be used morning and evening without restriction. In dry climates, always pair glycerin with a heavier moisturizer to prevent moisture evaporation.
Pairs Well With
Works with everything. Particularly effective with ceramides (hydrate + seal), hyaluronic acid (double humectant power), and squalane (humectant + emollient). Glycerin + ceramides is the backbone of most K-beauty barrier creams.
Avoid Combining With
No conflicts. Glycerin is the most universally compatible skincare ingredient. The only caution: don't use 100% pure glycerin undiluted, and always follow with a moisturizer in dry environments.