Humectant

Lactitol

INCI: LACTITOL

Reviewed by Emma · Last updated 14 Aug 2026

A sugar alcohol humectant that draws moisture into the skin and supports hydration

Best For Skin Types

All, Dry, Sensitive, Combination

Addresses

Dryness, Hydration, Dehydration

Usage Frequency

Daily

What Is Lactitol?

Lactitol is a sugar alcohol (polyol) derived from lactose, commonly used in skincare as a humectant and skin conditioning agent. Like other polyols such as glycerin and sorbitol, it has a molecular structure that allows it to attract and bind water molecules, making it useful in formulations designed to improve skin hydration.

In cosmetic products, lactitol works by drawing moisture from the environment and deeper skin layers to the surface, helping to maintain skin's water content. It also has mild skin-conditioning properties that can help improve the overall feel and texture of skincare formulations.

How It Works

Lactitol is hygroscopic, meaning it has an affinity for water molecules. When applied to skin, it draws moisture from the deeper layers of the epidermis and from the surrounding air, helping to plump and hydrate the outer skin layer. This action reduces the appearance of dryness and can temporarily improve skin smoothness and texture.

Unlike some other humectants, lactitol's mode of action is relatively straightforward — it functions primarily through water-binding rather than through deeper metabolic pathways. This makes it a gentle, well-tolerated option in skincare formulations.

Clinical Evidence & References

Lactitol's use in skincare is well-established in the cosmetic industry, though dedicated clinical studies specifically examining its efficacy in skincare products are limited in the published literature. Its effectiveness as a humectant is supported by its chemical properties and widespread use in formulation, but robust comparative data against other polyols is sparse.

The ingredient is generally recognised as safe for topical use and is unlikely to cause irritation in most individuals. However, individual skin responses can vary, and more targeted clinical research would help establish precise efficacy claims for specific skin concerns.

How to Use

Lactitol is typically found in serums, moisturisers, and hydrating toners at concentrations that support its humectant function. For best results, apply lactitol-containing products to clean, slightly damp skin to maximise water absorption. It works well in layered routines — apply before heavier creams to allow the humectant to do its work, then seal with an occlusive if needed in dry conditions.

Safety & Precautions

Lactitol is generally well-tolerated and considered safe for topical use on all skin types. It is not a known irritant or sensitiser, though those with extremely sensitive skin should patch-test as with any new ingredient.

Frequently Asked Questions

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