The Connection Most Labels Don't Explain

Colloidal oatmeal and beta-glucan both come from grains — most commonly oats, but also barley — so it's easy to treat them as interchangeable. However, that is not the case..

Colloidal oatmeal is finely milled oat grain suspended in a liquid or cream base. It contains a mix of compounds: proteins, lipids, starches, avenanthramides (anti-inflammatory polyphenols), and beta-glucan. When you apply a colloidal oatmeal product, all of these components interact with the skin simultaneously.

Beta-glucan is one specific polysaccharide within that mix, and it's responsible for a significant portion of what makes colloidal oatmeal effective. It's also found in meaningful concentrations in barley, where it has a similarly strong evidence base for skin benefits. When researchers have studied which components of these grains produce the most measurable benefit for barrier function and inflammation, beta-glucan consistently stands out, regardless of whether it's sourced from oats or barley.

So, it is more accurate to reframe our understanding this way: colloidal oatmeal has real benefits, and beta-glucan is a key reason why.

How Beta-Glucan Actually Works in the Skin

Understanding the mechanism matters, not just because it's interesting, but because it explains why concentration and purity make a difference.

Activating Skin Immune Receptors

Beta-glucan binds to a receptor on skin immune cells called Dectin-1. This binding triggers a cascade of skin-protective responses: it supports the skin's ability to defend against pathogens, promotes tissue repair signaling, and helps regulate the inflammatory response rather than suppressing it entirely.

This is a meaningfully different mechanism from topical corticosteroids, which broadly suppress local immune activity. Beta-glucan works more like a modulator to nudge the skin toward a more balanced immune state rather than shutting the response down. Importantly, this mechanism holds whether the beta-glucan is derived from oats or barley; the polysaccharide structure is similar enough across both sources to produce comparable receptor-level activity.

Supporting Wound Healing and Barrier Repair

Beta-glucan promotes the activity of cytokines (protein messengers of the immune system) involved in wound healing, including those that support collagen production and cell turnover. In practical terms: it helps damaged or inflamed skin move toward recovery more efficiently.

For children with eczema-prone skin where the barrier is structurally impaired and repeatedly broken this kind of active repair support has meaningful implications over time.

Reducing Transepidermal Water Loss

One of the central problems in eczema is transepidermal water loss: moisture escaping through a compromised outer skin layer faster than it can be replaced. Beta-glucan from both oat and barley sources has demonstrated the ability to reduce transepidermal water loss by supporting barrier structure and hydration retention. This is not just a cosmetic benefit, as lower transepidermal water loss means fewer flares.

Calming Inflammatory Markers

Pre-clinical studies on beta-glucan have shown reductions in inflammatory cytokines associated with eczema and sensitive skin conditions. Research on barley-derived beta-glucan, in particular, has shown comparable anti-inflammatory effects to oat-derived versions, suggesting that the source grain matters less than the purity and concentration of the compound itself. This isn't a cure, and results vary across individuals and formulations, but it does give beta-glucan a meaningful evidence base for the best ingredient for eczema conversations, particularly as part of a consistent daily routine.

Beta-Glucan vs. Colloidal Oatmeal: A Side-by-Side Comparison

Here's where the practical differences become clearer.

Concentration

This is the most important variable. Typical colloidal oatmeal products contain approximately 3–5% beta-glucan by weight. The rest is other oat components, carrier ingredients, and preservatives.

The By Dr. Mom bath soak contains 23% beta-glucan. That's a substantially higher concentration of the specific compound associated with barrier support and anti-inflammatory activity. When comparing products, this number matters: not because higher is always better in every context, but because the dose of an active ingredient determines how much biological work it can do.

Purity and Targeted Delivery

Colloidal oatmeal delivers beta-glucan alongside starches, proteins, and other components that don't offer the same skin-active benefits. Some of those components — especially starches — can contribute to the thick, sometimes sticky texture of traditional oatmeal formulations.

A product built around isolated or concentrated beta-glucan — whether sourced from oats or barley — delivers the active compound more directly, without the additional load of inactive material. Barley-derived beta-glucan, in particular, tends to have a high molecular purity and is well-suited to clean cosmetic formulations.

Absorption

Beta-glucan molecules come in different sizes. Hydrolyzed or lower-molecular-weight beta-glucan penetrates the outer skin layers more readily, which supports more efficient delivery of its barrier-supporting effects. Full-grain colloidal oatmeal largely remains on the skin surface, which still offers benefits — but is less targeted in terms of what reaches the deeper layers of the stratum corneum.

Clinical Evidence

Colloidal oatmeal has strong clinical support for use in eczema and sensitive skin. It is recognized by the FDA as a safe and effective skin protectant. Much of that evidence base, when examined closely, points to beta-glucan as the primary active contributor. Isolated beta-glucan studies — including research on both oat- and barley-derived sources — have shown consistent results for TEWL reduction, inflammatory marker suppression, and wound-healing support.

 

The Sensory and Usability Difference

If you are a parent, this section may provide more practical and useful information to keep in mind when selecting skincare products for the family. 

The Problem with Traditional Oatmeal Baths

Oatmeal baths have been recommended by pediatricians for generations, and for good reason. But any parent who has drawn one knows the challenges:

• The oatmeal can make the tub slippery, which is a safety concern with young children

• Fine oatmeal particles clog drains and require thorough cleanup

• The texture can feel gritty or leave a film on skin that some children find uncomfortable

• It's messy to measure and add, especially during a fussy eczema flare at bedtime

We likely can all empathize that a routine is inconvenient or unpleasant, families don't stick with it; however, consistency is the whole point of proactive eczema management.

What a Concentrated Beta-Glucan Format Offers

A clean, water-soluble beta-glucan soak dissolves fully in bathwater without leaving residue, grit, or drain-clogging particles. The bath experience is simpler, the cleanup is faster, and the concentration of the active compound is higher, which means you're getting more of what actually works with less of the friction that makes routines hard to maintain.

Whether the beta-glucan in that formula comes from oats, barley, or a combination of both, what matters is that the active compound is concentrated, pure, and delivered in a format that families will actually use consistently.

For families managing eczema in young children, removing that friction matters. The best skincare routine is the one that gets done every night.

What the Colloidal Oatmeal Skin Benefits Conversation Is Missing

Colloidal oatmeal deserves its strong reputation. It works. But "colloidal oatmeal" as a category includes everything from highly formulated, clinically supported products to diluted lotions that contain barely enough active compound to register.

When you see colloidal oatmeal on a label, the relevant question isn't just whether it's there — it's how much beta-glucan the product actually delivers. That number is rarely disclosed on standard colloidal oatmeal products, which makes direct comparison difficult for consumers.

It's also worth knowing that beta-glucan isn't exclusive to oats. Barley is another well-studied grain source, and barley-derived beta-glucan has demonstrated meaningful skin benefits in its own right. If you see beta-glucan listed on a label without an oat source specified, it may well be barley-derived, and that's not a downgrade. The clinical relevance of the compound holds across both plant sources.

Choosing a product that specifies its beta-glucan concentration regardless of source gives you a more honest basis for comparison.

What to Look For When Choosing Between These Ingredients

If you're evaluating a colloidal oatmeal product:

• Look for it listed in the first five to six ingredients (indicating higher concentration)

• Confirm the formula is fragrance-free. Colloidal oatmeal's benefits are undermined quickly by fragrance-related irritation

• Check for complementary ingredients like ceramides or glycerin that support barrier function

If you're considering a beta-glucan product:

• Look for a disclosed concentration. Higher than the 3–5% typical of colloidal oatmeal products suggests more active compound

• Note the source (oat or barley) if disclosed. Both are effective, and either is a good sign

• Confirm the molecular weight or hydrolyzation is specified if the brand provides that detail (lower molecular weight means better absorption)

• Fragrance-free and dye-free remain non-negotiable for sensitive or eczema-prone skin

The Bottom Line

Colloidal oatmeal and beta-glucan aren't in competition — they're related. But understanding the relationship helps you make a more informed decision about what you're actually applying to sensitive skin.

Beta-glucan is a naturally occurring compound found in both oats and barley, and the research supporting its skin benefits spans both sources. Whether extracted from one grain or the other, it works through the same core mechanisms: Dectin-1 activation, inflammatory modulation, TEWL reduction, and wound-healing support. When delivered at meaningful concentrations in a clean, usable format, it addresses the underlying barrier dysfunction that drives eczema flares — not just the symptoms.

If you're looking for products formulated around this science, the by Dr. Mom bath soak and barrier cream at bydrmom.com are built with exactly this approach: physician-informed, ingredient-specific, and designed for families who want daily skincare that actually supports their child's skin long-term.

Frequently Asked Questions

Can I use beta-glucan and colloidal oatmeal together?
Yes. They work through complementary mechanisms and are well-tolerated together. If a product contains both, that's generally a positive sign.

Is beta-glucan from barley as effective as beta-glucan from oats?
The available evidence suggests that barley-derived beta-glucan offers comparable skin benefits to oat-derived beta-glucan. Both interact with the same skin receptors and support similar barrier-repair and anti-inflammatory responses. The source matters less than the concentration and purity of the compound.

Is beta-glucan safe for babies?
Beta-glucan derived from oats or barley is well-tolerated by infants and has no known safety concerns at typical cosmetic use concentrations. It's one of the few ingredients with both efficacy evidence and a favorable safety profile for very young children.

How long does it take to see results from beta-glucan use?
Barrier repair takes time. Most clinical evidence for barrier-supportive ingredients shows meaningful changes over four to eight weeks of consistent use. Daily application matters more than any single application.

REFERENCES

Jesenak, M., Banovcin, P., Rennerova, Z., & Majtan, J. (2014). β-Glucans in the treatment and prevention of allergic diseases. Allergologia et Immunopathologia, 42(2), 149–156. https://doi.org/10.1016/j.aller.2012.08.008 

Stojadinovic, O., Kirsner, R. S., & Tomic-Canic, M. (2021). The role of β-glucan in skin repair and regeneration. International Journal of Molecular Sciences, 22(16), 8553. https://doi.org/10.3390/ijms22168553

Du, B., & Xu, B. (2014). Skin health promotion effects of natural beta-glucan derived from cereals and microorganisms: A review. Phytotherapy Research, 28(2), 159–166. https://doi.org/10.1002/ptr.4963 

Majtan, J., & Jesenak, M. (2018). β-Glucans: Multi-functional modulator of wound healing. Molecules, 23(4), 806. https://doi.org/10.3390/molecules23040806 

Chaudhary, M., Vowden, K., Vowden, P., & Hurlow, J. (2025). Effect of beta-glucan on wound healing: A systematic review and meta-analysis. Wound Practice and Research, 33(4). https://journals.cambridgemedia.com.au/wpr/volume-33-number-4/effect-beta-glucan-wound-healing-systematic-review-and-meta-analysis

Vetvicka, V., & Vetvickova, J. (2017). β-Glucan improves conditions of chronic fatigue syndrome in murine model. Journal of Natural Science, Biology and Medicine, 8(2), 179–183. https://doi.org/10.4103/jnsbm.JNSBM_104_17