No. 2 Protein 43% Creamy Serum

In the crowded arena of barrier-repair serums, the default formula is predictable: ceramides, maybe some cholesterol, possibly panthenol, call it a day. Numbuzin looked at that playbook and asked a question that deserves more attention — what about the protein half of the barrier equation?

The skin barrier isn't just a lipid sandwich. The corneocytes — those flattened, protein-rich cells that form the bricks in the brick-and-mortar model — are held together by structural proteins like filaggrin and involucrin. Most barrier-repair products focus exclusively on the mortar (lipids), leaving the bricks to fend for themselves. This serum's headline move is putting protein front and center, with Avena Sativa kernel extract at 43% concentration as the very first ingredient.

That oat extract isn't just filler volume. Oat proteins deliver amino acids that serve as building blocks for the skin's natural moisturizing factor (NMF), while oat-derived beta-glucans form a thin hydrating film and avenanthramides provide anti-inflammatory action. The result is a protein base that simultaneously soothes, hydrates, and provides raw materials for barrier reconstruction.

But Numbuzin didn't stop at protein. Smartly, they layered in the lipid side too — Ceramide NP with cholesterol and fatty acids (palmitic, stearic, myristic, arachidic, lauric) in ratios that approximate the skin's natural lipid composition. This dual approach means you're supporting both the bricks and the mortar, which is theoretically more complete than either strategy alone.

The supporting cast is strong. Niacinamide sits mid-list, providing its characteristic versatility — stimulating endogenous ceramide production, evening skin tone, and managing sebum. Panthenol adds another layer of recovery support, accelerating wound healing and providing deep hydration. Allantoin soothes. Adenosine, the K-beauty industry's quiet workhorse, contributes anti-wrinkle benefits. And a Lactobacillus ferment lysate nods to microbiome support, rounding out an impressively comprehensive approach to skin recovery.

The texture experience leans luxurious. This is unmistakably a silicone-forward serum — cyclopentasiloxane and phenyl trimethicone create that distinctive primer-like slip that makes skin feel instantly smooth and refined. If you enjoy the tactile experience of a serum that transforms your skin's surface the moment it touches down, this delivers. A pea-sized amount spreads effortlessly across the entire face, absorbing into a satin finish that works under makeup or sunscreen without pilling.

Here's where the conversation gets honest. That silicone base is polarizing. For dry and normal skin types who want both treatment and a smooth canvas, it's a feature. For oily skin types or anyone who prefers water-based formulations, it's a dealbreaker. The silicones don't make the actives less effective, but they do contribute a richness that not every skin type wants sitting on its face.

The fragrance issue deserves its standard callout. For a serum explicitly targeting compromised barriers, including fragrance is a puzzling choice. It's the last ingredient on the list, suggesting minimal concentration, and it does dissipate quickly. But when your entire product philosophy is built around healing damaged skin, even a small amount of fragrance potential irritant feels like an unforced error.

The protein diversity is worth noting — beyond the oat base, there are hydrolyzed proteins from rice, milk, soy, lupine, corn, pea, sweet almond, and generic vegetable sources. This creates an amino acid profile broader than any single protein source could provide. However, it also introduces allergen concerns for anyone sensitive to dairy, soy, or tree nuts.

Performance-wise, this serum earns its reputation. Within the first week, expect calmer, less reactive skin with reduced tightness and flaking. By week three or four, the cumulative barrier strengthening becomes apparent — skin holds moisture better, tolerates active treatments more easily, and has a plumper, more resilient quality. The improvements are gradual and genuine, not just surface-level smoothing from the silicones.

At approximately fifteen dollars for 50ml, the value is reasonable given the active ingredient density. You're getting ceramide NP, niacinamide, panthenol, adenosine, and a 43% oat protein base — that's a lot of functional ingredients for a K-beauty price point. The small tube lasts longer than expected because the silicone slip means a little covers a lot of surface area.

This is a serum that rewards patience and consistency. It's not flashy, it won't transform your skin overnight, and it makes no viral-worthy claims. What it does is quietly rebuild, session after session, using a broader toolkit than most of its competitors bother assembling.

Formula

The Science

The theoretical foundation of this serum rests on the brick-and-mortar model of the stratum corneum, first characterized by Peter Elias in the 1980s. In this model, corneocytes (protein-rich dead cells) form the bricks, held together by a lipid matrix (ceramides, cholesterol, free fatty acids) that forms the mortar. Most barrier-repair products address only the lipid side — this formula attempts to support both.

Avena Sativa (oat) protein provides amino acids that contribute to the skin's natural moisturizing factor (NMF). A 2007 study in the Journal of Drugs in Dermatology demonstrated that colloidal oatmeal formulations significantly improved skin barrier function, reduced transepidermal water loss, and decreased markers of inflammation in patients with compromised barriers. The avenanthramides in oat are particularly well-studied — a 2008 paper in Archives of Dermatological Research confirmed their anti-inflammatory activity through inhibition of NF-kB and pro-inflammatory cytokines.

Ceramide NP paired with cholesterol and free fatty acids mirrors the skin's natural lipid composition. Research published in the Journal of Investigative Dermatology has established that topical application of these three lipid classes in physiological ratios accelerates barrier recovery more effectively than any single lipid applied alone. The inclusion of five fatty acids (palmitic, stearic, myristic, arachidic, lauric) in this formula provides a broader fatty acid profile than most single-ceramide products.

Niacinamide's ability to stimulate endogenous ceramide synthesis was demonstrated in a 2000 study in the British Journal of Dermatology, which found that topical niacinamide increased ceramide and free fatty acid levels in the stratum corneum. In this formula, it creates a feedback loop — the exogenous Ceramide NP provides immediate barrier repair while niacinamide promotes the skin's own ceramide production for sustained recovery.

Panthenol (provitamin B5) converts to pantothenic acid in the skin, where it stimulates fibroblast proliferation and accelerates re-epithelialization. A review in the Journal of Cosmetic Dermatology documented panthenol's wound-healing properties and its role as a deep-penetrating humectant.

References

1. Colloidal oatmeal: history, chemistry and clinical properties — Journal of Drugs in Dermatology (2007)
2. Anti-inflammatory activities of colloidal oatmeal (Avena sativa) contribute to the effectiveness of oats in treatment of itch associated with dry, irritated skin — Archives of Dermatological Research (2008)
3. Niacinamide increases biosynthesis of ceramides as well as other stratum corneum lipids — British Journal of Dermatology (2000)

Dermatologist Perspective

Board-certified dermatologists frequently recommend barrier-repair formulations containing ceramides, cholesterol, and fatty acids for patients recovering from over-exfoliation, retinoid irritation, or environmental barrier damage. This serum's protein-forward approach is less conventional but aligns with emerging understanding that barrier health depends on both the protein and lipid components of the stratum corneum. Dermatologists would likely appreciate the inclusion of niacinamide and panthenol alongside ceramide NP, though they would note that the fragrance is an unnecessary risk for patients with compromised barriers. For patients with dairy or soy allergies, this product warrants a patch test or alternative recommendation.

Guidance

Numbuzin's No. 2 line focuses on skin strengthening and recovery, and this serum represents the brand's most ambitious formulation in that category. The 43% protein concentration became a talking point in Korean beauty communities, where it positioned itself as a science-forward alternative to the ceramide-only barrier creams dominating the market.

About Numbuzin Emerging Brand (2–5 years)

Numbuzin launched in 2019 under Korean startup Benow and quickly gained traction after winning top honors at the 2022 Olive Young Awards. The brand is known for its numbered product system and ingredient transparency, though it has a limited track record and no independent clinical trials on its specific formulations.

Brand founded: 2019 · Product launched: 2022

Myth vs. Reality

Myth

Protein-based skincare can cause allergic reactions in everyone with food allergies.

Reality

While this serum does contain hydrolyzed milk, soy, and almond proteins that could trigger contact reactions in sensitized individuals, topical protein allergies don't perfectly overlap with food allergies. However, if you have known allergies to these foods, patch testing is strongly recommended before full-face application.

Myth

Silicone-heavy serums just sit on top of the skin and don't actually deliver actives.

Reality

The cyclopentasiloxane and phenyl trimethicone in this formula serve as delivery vehicles that help spread active ingredients evenly while creating an occlusive-like layer that reduces transepidermal water loss. The actives — niacinamide, panthenol, ceramide NP — are still absorbed through the stratum corneum; the silicones simply improve the application experience and help lock in hydration.

FAQ

Common Praise

"Silky, luxurious texture that absorbs without greasiness"

"Noticeable improvement in skin firmness and barrier strength after weeks of use"

"A little goes a long way — the 50ml tube lasts longer than expected"

"Skin feels plumper and more hydrated without heavy residue"

Common Complaints

"Contains fragrance which may irritate reactive skin"

"Heavy silicone base can feel occlusive for oily skin types"

"Contains milk and soy proteins — not suitable for those with relevant allergies"

"Premium price point for a K-beauty serum"

Notable Endorsements

2022 Olive Young Awards brand recognition

Appears In

best serum for compromised skin barrier best k beauty serum for sensitive skin best barrier repair serum best protein serum for dry skin

Related Conditions

compromised skin barrier sensitivity dryness dehydration aging

Related Ingredients

colloidal oatmeal niacinamide ceramides panthenol adenosine