Humectant
Humectant — an ingredient that attracts and binds water into the upper layers of the skin, drawing moisture from deeper layers or the surrounding air. This helps keep the surface hydrated, plump, and supple.
Key points
- Humectants work by chemically attracting water molecules and holding them within the stratum corneum.
- Common humectants include glycerin, hyaluronic acid, sodium PCA, urea, propylene glycol, and honey.
- In very dry or low-humidity environments, humectants can pull water from deeper skin layers, so pairing them with an occlusive helps lock hydration in.
- They are found in many serums, toners, and moisturizers to boost surface hydration and improve skin feel.
Frequently asked
Should I apply humectants to damp or dry skin?
Humectants generally perform best on slightly damp skin, giving them water to bind to. Following with an occlusive or emollient helps seal in the moisture.
Can humectants dry out my skin?
In very dry air, humectants may draw water from deeper skin layers rather than the environment, which can feel drying if moisture then evaporates. Layering an occlusive on top helps prevent this.
Related topics
This is a foundational entry in the SYNC Skin Encyclopedia and is expanded over time. Educational information only — not medical advice.
