Urea
A natural moisturizing factor (NMF) present in the stratum corneum. Low concentrations moisturize; high concentrations act as a keratolytic. The gold standard for hyperkeratosis and xerosis.
Evidence by route
Topical application
Dozens of RCTs and dermatological society guidelines confirm efficacy for xerosis, atopic dermatitis, and hyperkeratosis. Reduces TEWL, restores NMF, and enhances penetration of other active ingredients.
- Basic Emollients for Xerosis Cutis in Atopic Dermatitis: A Review of Clinical Studies. Int J Dermatol. 2025.. PMID 40265493
How to read tiers A–F
- AProven efficacy. Two or more independent RCTs with instrumental endpoints
Tolerability and safety
- Working concentrations
- 2–10% for hydration; 20–40% for keratolytic effect
- Irritation potential
- Low
- Allergen risk
- Low
- Pregnancy
- Safe
- Suitable for
- Dry, Normal, Sensitive, Combination
For sensitive skin
At concentrations above 10%, it may sting on damaged or inflamed skin. Start at 5%.
About this ingredient
Urea (carbamide) is a natural moisturising factor (NMF) present in the stratum corneum at 0.1-1%. The end product of mammalian protein metabolism. Used in dermatology since the 1940s – one of the most studied topical ingredients. Mechanism – dose-dependent. At low concentrations (2-10%) urea works as a humectant, retaining water in the stratum corneum and supporting filaggrin activity. At medium (10-20%) – penetrates deeper and improves hydration of atopic and xerotic skin. At high (20-40%) – keratolytic, breaks intercorneocyte bonds, used for hyperkeratosis (feet, elbows, palms, nails). Above 40% – antifungal against yeasts. Where applied. Eucerin UreaRepair (5%, 10%), CeraVe Renewing SA Foot Cream (10% urea), Isdin Ureadin (5-40%), La Roche-Posay Iso-Urea, Avène Akerat. The broadest range in Spain is the Isdin Ureadin line for various skin types and body areas. Evidence base. Pan 2013 meta-analysis of 22 studies and 1200+ patients confirmed 10% urea efficacy in atopic dermatitis – TEWL reduction 25-35%, SCORAD improvement 30-40% over 4-8 weeks. AAD 2024 and NICE 2024 include urea as first-line for atopic dermatitis, xerosis, and ichthyosis. For foot hyperkeratosis – 20-40% urea combined with 5% salicylic acid. Safety. CIR confirmed safety at all concentrations in 2005. Burning is possible above 20% on thin facial skin or broken skin. Non-sensitising, non-comedogenic. Pregnancy and lactation – safe. One of the preferred agents during pregnancy for dry skin, hyperkeratosis, acne (10% urea + 1% salicylic) and atopy. AEMPS and FDA – without restrictions. Suited for. Atopic dermatitis, xerosis, ichthyosis, hyperkeratosis of feet and elbows, keratosis pilaris (KP), foot fungal infections, acne (combined with other actives). Not suitable for rosacea and perioral dermatitis at high concentrations.
Frequently asked questions
Is Urea safe during pregnancy?
Urea is considered safe during pregnancy at typical cosmetic concentrations. Systemic absorption through the skin is minimal.
What skin types is Urea for?
Urea suits: dry, normal, sensitive, combination.
What is Urea and what does it do in cosmetics?
A natural moisturizing factor (NMF) present in the stratum corneum.
What's the INCI name for Urea?
The INCI name is Urea. It may also appear as: Carbamide.
What concentration of Urea is effective?
2–10% for hydration; 20–40% for keratolytic effect
See Urea in a product composition right on the store page
The Evigrade extension adds an evidence panel to iHerb, Sephora, Druni and 12 more stores. This ingredient and every other one in the product show evidence-tier, allergen risk and pregnancy/lactation flags at a glance.
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