Urea

Humectant2–10%

A skin-identical moisturiser that softens rough, dry skin on elbows, knees, heels and hands.

What it is

Urea is part of the skin's own natural moisturising factor, made in the lab for skin care. At low levels it draws water into the skin, and at higher levels it also softens thick, rough patches. It suits dry body skin, hands and feet, and is a staple of skin-care-style body ranges.

Good for

Dry skinRough textureRough heels and elbowsBumpy upper arms

How it works

Urea is a small, water-loving molecule that holds water in the outer layer of skin. At higher levels it also loosens thick, dead surface skin by breaking hydrogen bonds in keratin. As it is very water-soluble, it suits light, non-greasy lotions as well as richer creams.

Ratings

Evidence

4/5

Good clinical support for dry skin at 2–10%, less at higher levels.

Gentleness

4/5

Well tolerated at 2–10%, but can sting on very dry skin.

Formulation difficulty

3/5

Slowly breaks down in water, raising pH and causing ammonia odour.

Cost

1/5

Inexpensive commodity raw material.

Popularity

4/5

Prominent in the move to skin-care-style body lotions.

Pairs and cautions

Pairs well with

In a routine. Pairing in one formula depends on matching pH windows.

Take care with

True soaps and other high-pH basesSpeed its breakdown

Formulations it suits

Lotion Cream Hand cream Body wash

Packaging

Regional considerations

Australia	Listed in Appendix B of the Poisons Standard (low toxicity, any use), so it is unscheduled at any strength. Claims to treat eczema, psoriasis or other skin conditions make it a therapeutic good.
Canada	Health Canada caps urea at 10% in cosmetics other than bath products, so 20–40% heel and callus creams cannot be sold there as cosmetics.
Climate	Urea breaks down faster as temperature rises, releasing ammonia and pushing pH up. Buffer near pH 6 (lactate works best) and stability-test at 40°C before shipping to hot markets.

In the lab

Specifications

Typical use level

2–10%0525%

pH window

pH 5.5–72 acid7 neutral10 alkaline

Solubility

Water-soluble

Sensitive to

WaterHeatHigh pH

Daily body lotions use 2–5% and rough-skin creams 10%. Specialist heel and callus creams go to 20–40%, where urea also softens thick skin.

INCI	Urea
Also known as	Carbamide
Origin	synthetic

Lab notes

Solubility and phase

Water phase. It is very soluble.

Stability

Add below 40 °C and buffer near pH 6, often with lactate, to slow its breakdown to ammonia and carbon dioxide. Track pH and odour drift through stability testing.

Regulatory, Australia

Cosmetic ingredient in Australia, with introduction regulated by AICIS. Listed in Appendix B of the Poisons Standard, so it does not require scheduling.

Claims to take care with

Cosmetic claims include 'softens rough, dry skin' and 'smooths the look of bumpy skin'. Claims to treat eczema, psoriasis or ichthyosis, or to heal cracked, damaged skin, are therapeutic (TGA).