Urea (Carbamide)
Skincare ingredient, decoded — every claim sourced.
What it is
A water-binding humectant at lower strengths and a gentle keratolytic (softens and helps shed rough, dry-looking skin) at higher strengths.
How it works
Urea is part of the skin's own Natural Moisturizing Factor, so applying it tops up a molecule the stratum corneum already uses. As a hygroscopic (water-attracting) agent it pulls water into the outer skin layer, reduces transepidermal water loss and increases the stratum corneum's resistance to drying stress. At higher concentrations it softens keratin by loosening the hydrogen bonds and protein structure that hold thickened, scaly-looking skin together, which is the keratolytic (skin-shedding) action that smooths rough texture. Beyond simple hydration, urea has been reported to support the skin's own barrier proteins — filaggrin, loricrin and transglutaminase-1 — and to raise the skin's own antimicrobial peptides cathelicidin and beta-defensin-2, which is why it is described as barrier-supporting rather than merely surface-moisturizing. It is also documented to increase the skin penetration of other topically applied ingredients, so it can make a formula's other actives reach the skin more readily.
Works well with
CeramidesGlycerinHyaluronic AcidLactic Acid (in formulated keratolytic creams)NiacinamidePetrolatum / occlusives
Introduce carefully alongside
Multiple strong exfoliating acids at once (cumulative irritation on the face)High-strength retinoids on already-sensitive or broken skinOther high-concentration keratolytics layered on the same area
Who should take care
Skip or patch-test first if you have very sensitive, broken, cracked or visibly inflamed skin, as higher-strength urea can sting on compromised areas. Be cautious layering strong (20%+) urea on the face or with other exfoliating ingredients. Low-strength urea moisturizers are generally considered a gentle, low-concern choice; if you are pregnant or breastfeeding and are considering a high-strength keratolytic product, it is sensible to keep to lower concentrations and consult a doctor first. For infants and young children, also keep to low concentrations. This is general cosmetic-reference guidance, not medical advice.
🔒 IN THE APP
The dose that actually works — and is it right for your skin?
The concentration that actually makes a difference, and whether this fits YOUR skin profile, lives in the MHS BLOOM app.
Sources
- Piquero-Casals J, et al. Urea in Dermatology: A Review of its Emollient, Moisturizing, Keratolytic, Skin Barrier Enhancing and Antimicrobial Properties. Dermatol Ther (Heidelb). 2021 (PMC8611129 / PMID 34596890 — same article). Supports the NMF role, the dose tiers (2–10% humectant, 10–30% medium/keratolytic, ~30%+ and 40–50% strong keratolytic), TEWL reduction, keratin softening via hydrogen-bond disruption, penetration enhancement, and the upregulation of filaggrin/loricrin/transglutaminase-1, cathelicidin and beta-defensin-2.
- Cosmetic Ingredient Review Expert Panel. Final report of the safety assessment of Urea. Int J Toxicol. 2005;24 Suppl 3:1-56 (PMID 16422263). Documents actual cosmetic use concentrations ranging from 0.01% to 10%, the conclusion that urea is safe as used in cosmetic products, and that urea can increase the skin penetration of other ingredients — supporting the use-concentration range, the safety-assessment (rather than fixed-cap) framing, and penetration enhancement.
- Sethi A, Kaur T, Malhotra SK, et al. Moisturizers. In: StatPearls. NCBI Bookshelf (NBK545171). Supports urea as an NMF component and humectant that aids water absorption into the stratum corneum, promotes corneocyte desquamation, improves barrier function, reduces TEWL, and increases penetration of other topically applied ingredients. (Does not address filaggrin/loricrin/transglutaminase-1 or antimicrobial-peptide upregulation.)
This is not medical advice at all — cosmetic information only. Not suitable during pregnancy or breastfeeding; always consult your doctor.