Humectant vs Occlusive
Humectant vs Occlusive — two categories of moisturizing ingredients that work in different ways, where humectants attract and bind water into the upper layers of skin and occlusives form a protective film on the surface that slows water from evaporating. They are frequently combined for balanced hydration.
Key points
- Common humectants include glycerin, hyaluronic acid, and urea, which pull in water from the environment and deeper skin.
- Common occlusives include petrolatum, shea butter, and various oils, which create a barrier to reduce transepidermal water loss.
- In low-humidity environments, humectants used alone can potentially draw water out of deeper skin, so an occlusive on top helps lock it in.
- A third category, emollients, primarily smooths and softens skin and often overlaps in function with occlusives.
Frequently asked
Should I apply humectants or occlusives first?
Generally humectants go on first to attract water, followed by occlusives to seal that moisture in, especially on damp skin.
Is one better than the other?
Neither is inherently better; they serve different roles, and many effective moisturizers blend humectants and occlusives to both add and retain water.
Related topics
This is a foundational entry in the SYNC Skin Encyclopedia and is expanded over time. Educational information only — not medical advice.
