Allantoin in skincare: what it is and what has been tested

The rat study

The study most often cited as evidence for allantoin used 60 female Wistar rats with open wounds, split into three groups: no treatment, an oil-in-water lotion without allantoin, and the same lotion with 5% allantoin. It was applied for 14 days and the wounds were measured and examined under the microscope. The authors suggest allantoin works by regulating the inflammatory response and stimulating fibroblasts and the production of extracellular matrix, and that it can ameliorate and speed the return to normal skin.¹

It is a clean study, but it is in rats, with a deliberate open wound. That is a different situation from using a cream with a trace of allantoin on dry or irritated human skin.

What we found in people

The human trial we found tested a combined product, an onion extract with heparin and allantoin, against two silicone products for burn scars over six months. All three improved scar scores, but the silicone gel and sheet were superior to the combined product.²

A second trial also tested a mix. In 125 adults with scars from minor skin surgery, an overnight patch containing onion extract and allantoin was compared with no treatment on the other scar of the same person, over 12 to 24 weeks. Observer-rated scar scores improved more on treated scars at week 6.³ There was no arm for the allantoin or the onion extract alone, so the result cannot be credited to either.

Because that product contained other active ingredients, it tells you little about allantoin itself. We did not find a controlled trial of allantoin alone on human skin.

That does not mean it does nothing. It means that when a label lists allantoin, it is being used for the claim that has the least direct evidence behind it of the ingredients in this section.

Using allantoin with other products

We did not find a source saying allantoin clashes with any other ingredient, and we did not find studies of it layered with actives either. Given how thin the evidence for allantoin is on its own, there is little to say beyond adding one product at a time, so you know which one is responsible if your skin reacts.

What the safety review found

The Cosmetic Ingredient Review expert panel assessed allantoin and six allantoin complexes in 2010. Allantoin was reported in 1,376 cosmetic products at concentrations up to 2%, and the panel judged the test data sufficient to support its safety in the product categories and concentrations reviewed.⁴ The review also noted data gaps on use and concentration for some of the complexes. The panel was set up in 1976 by the cosmetics industry’s trade association, with support from the US Food and Drug Administration and the Consumer Federation of America.⁵

That is a statement about safety at cosmetic strengths. It is not evidence that allantoin does anything for skin, which is the separate question the trials above try to answer.

Allantoin in pregnancy and breastfeeding

Evidence on cosmetic products in pregnancy is limited overall, so ask your doctor or midwife about the specific product you use.⁶

What you will see on the label

On a label, look for Allantoin. Snifff shows it as Risk-free. For the rest of the formula, see what the score means and how to read the list.

As Snifff shows it

Allantoin

Risk-free

Pregnancy and nursing

We found no pregnancy- or lactation-specific evidence for this ingredient.

Wording as it appears in the extension, which can change between releases.