Beginner·Explainer·5 min
How hair products work
Hair products divide into three functions: removing material from hair and scalp, improving the surface of the fibre, and holding a shape.
HairUnderstanding moisturizers
Three ingredient roles, combined in different proportions.
By HELM Editorial · EditorialUpdated 8/9/2026
Key takeaways
- —Humectants attract and hold water.
- —Emollients smooth the surface and improve feel.
- —Occlusives slow the rate at which water evaporates.
- —Most products combine all three; the ratio determines the texture.
Moisturiser is a category name, not a mechanism. Underneath, nearly all of them are combinations of three ingredient roles in different proportions.
Humectants
Humectants attract and hold water. Glycerin is the most widely used example. On its own, a humectant-heavy product can feel hydrating but leave the surface losing water quickly in dry air.
Emollients
Emollients sit between surface cells and smooth them, which is why skin feels softer and looks more even after application. They deliver most of what people describe as the feel of a moisturiser.
Occlusives
Occlusives form a layer that slows the rate at which water evaporates from the surface. Heavier occlusives feel richer and are useful in dry, cold conditions; lighter ones suit humid climates and oilier skin.
Choosing one
Start from conditions rather than category names. Dry air and tight skin call for more emollient and occlusive content. Humid conditions and oilier skin usually favour lighter, more humectant-driven textures. Change one product at a time and give it a fair trial before judging it.
Terms in this article
- Humectant
- An ingredient used to attract or retain water within a cosmetic system or at the application surface.
- Emollient
- An ingredient that softens and smooths the surface, typically by filling gaps between surface cells and improving slip.
- Occlusive
- An ingredient that forms a layer on the surface which slows the rate at which water evaporates from it.
Related HELM products
Read next