What Is Beta-Glucan?
Beta-glucan is a polysaccharide, meaning it is built from long chains of glucose molecules. It occurs naturally in oats, barley, yeast, and certain mushrooms. In skincare, oat-derived and yeast-fermented beta-glucan are the most common. On an ingredient list, look for 'beta-glucan', 'oat beta-glucan', or 'sodium carboxymethyl beta-glucan'.
As a polysaccharide humectant, it appears frequently in the same routines as hyaluronic acid and panthenol. Beyond moisturizing, its soothing properties make it a useful addition for sensitive skin and for routines that include potentially irritating actives.
How It Works in Skin
Beta-glucan works through two main pathways.
First, it forms a moisture-retaining film. The viscous polysaccharide chains create a thin layer over the stratum corneum that slows transepidermal water loss (TEWL). Where hyaluronic acid actively draws moisture from the environment into the skin, beta-glucan is more focused on keeping what is already there.
Second, it engages glucan receptors in the skin to deliver a soothing effect. Skin contains receptors that recognize beta-1,3-glucan structures, and binding to these receptors is thought to help regulate the skin's defense response, easing irritated or reactive skin. This soothing pathway is distinct from what hyaluronic acid offers.
Why Oat-Derived Beta-Glucan Is So Common
Oats are a reliable source of beta-glucan, with high concentrations and a well-standardized extraction process. The FDA recognizes colloidal oatmeal under 21 CFR 347 as an over-the-counter skin protectant, and there is a substantial body of clinical evidence for its role in soothing skin.
Yeast-fermented beta-glucan is also widely used in cosmetics. It shares the same beta-1,3/1,6-glucan structure as the oat-derived form, and may be a better option for those with oat sensitivities.
How It Differs from Hyaluronic Acid
| Property | Beta-Glucan | Hyaluronic Acid |
|---|---|---|
| Type | Polysaccharide (glucose polymer) | Glycosaminoglycan |
| Main source | Oats, yeast | Microbial fermentation |
| Hydration method | Moisture film (occlusion-like) | Moisture attraction (humectant) |
| Soothing effect | Yes (glucan receptor pathway) | Minimal |
| Used together | Complementary pathways; effective in combination | |
The two ingredients are complementary. Hyaluronic acid draws moisture in; beta-glucan creates a film that holds it there. Using both extends the duration of hydration. For skin that is irritated or reactive, beta-glucan's soothing action adds an additional benefit that hyaluronic acid does not provide.
What to Pair It With
- Hyaluronic acid: Covering both moisture attraction and moisture retention in one routine. Apply hyaluronic acid first, then layer a product containing beta-glucan on top.
- Ceramides: Ceramides fill lipid gaps in the stratum corneum while beta-glucan maintains surface moisture, providing layered barrier support.
- Panthenol: Both ingredients are focused on soothing and hydrating, making them a natural pairing for sensitive and dry skin routines.
- Retinol and AHA: Beta-glucan can help offset the dryness and mild irritation that actives sometimes cause, particularly at the start of use. Finishing a retinol step with a beta-glucan moisturizer is a common approach.
