Allantoin

Skin conditioner0.1–0.5%

A gentle skin-conditioning ingredient that helps dry, rough skin feel softer and more comfortable.

What it is

Allantoin occurs naturally in comfrey but is now usually made in the lab. It softens dry, rough skin and makes products feel more comfortable on sensitive or chapped areas. It is a quiet supporting ingredient in body lotions, hand creams, lip balms, baby care and after-sun.

Good for

Dry skinRough textureChapped lipsSensitive skinSun-exposed skin

How it works

Allantoin helps loosen and smooth rough surface cells and holds a little water in the skin, so dry patches feel softer. It is also thought to calm the look of irritation, which is why it appears in comfort-focused products.

Ratings

Evidence

2/5

Long use and US skin-protectant status, but few modern trials.

Gentleness

5/5

Very low irritation and found safe at use levels up to 2%.

Formulation difficulty

2/5

Only about 0.5% dissolves in water, and more can recrystallise.

Cost

1/5

Inexpensive commodity raw material.

Popularity

3/5

Common as a supporting ingredient with little pull on its own.

Pairs and cautions

Pairs well with

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

Take care with

Bases above about pH 9It breaks down

Formulations it suits

Lotion Hand cream Lip balm Balm Shampoo After-sun gel

Packaging

Regional considerations

Australia	Unscheduled cosmetic ingredient. Claims about healing cuts or burns or repairing damaged skin make the product a therapeutic good, so US cut-and-burn protectant claims do not carry over.
United States	At 0.5–2% allantoin is an OTC skin-protectant drug active, so products can claim to protect minor cuts, scrapes, burns and chapped skin, but only as drugs with a Drug Facts panel.

In the lab

Specifications

Typical use level

0.1–0.5%0525%

pH window

pH 4–92 acid7 neutral10 alkaline

Solubility

Water-soluble

Sensitive to

High pH

Most creams use 0.1–0.5%, with use up to 2% reported. Only about 0.5% dissolves in water at room temperature, so higher levels are carried as a fine suspension.

INCI	Allantoin
Also known as	Comfrey-derived compound (now usually made synthetically), Glyoxyldiureide
Origin	synthetic

Lab notes

Solubility and phase

Water phase, where about 0.5–0.6% dissolves at 25 °C, as it barely dissolves in alcohols or glycols and not at all in oils. Above about 0.5%, add it during cooling below 50 °C so it stays as a fine suspension rather than forming crystals; clear gels need to stay at or below about 0.5%.

Stability

Formulate within pH 4–9, where it is stable in water-based products.

Regulatory, Australia

Cosmetic ingredient in Australia (AICIS), not listed in the Poisons Standard, and found safe as used by CIR (2010). Its US over-the-counter skin protectant status does not carry over to Australia.

Claims to take care with

Cosmetic claims include 'softens', 'conditions' and 'comforts dry skin', while 'heals chapped or cracked skin', 'protects minor cuts' or 'relieves irritation from rashes' are therapeutic (TGA).