What is DMDM hydantoin in skincare?

DMDM hydantoin preserves products by slowly releasing small amounts of formaldehyde.

Evidence

Source:: de Groot AC et al. Contact Dermatitis. 2010;62(1):2-17
Applies to:: Formulations containing dmdm hydantoin
What this does not establish:: How a given product performs on your skin. Finished-product pH and concentration are rarely published, so this describes the chemistry, not a measurement of any specific product.
Last reviewed:: 2026-09-26

In practice

This preservative works by slowly releasing formaldehyde at levels regulators consider safe for cosmetic use. It is nonetheless a recognised contact allergen and a relevant one to know about if you have had a positive patch test to formaldehyde or to any formaldehyde-releasing preservative.

Dermasift analyses skincare formulations against published cosmetic science. This is information, not medical advice — for a diagnosed skin condition, speak to a dermatologist.

Check this against a product’s ingredient list

What is DMDM hydantoin in skincare?

DMDM hydantoin preserves products by slowly releasing small amounts of formaldehyde.

Evidence

Source:: de Groot AC et al. Contact Dermatitis. 2010;62(1):2-17
Applies to:: Formulations containing dmdm hydantoin
What this does not establish:: How a given product performs on your skin. Finished-product pH and concentration are rarely published, so this describes the chemistry, not a measurement of any specific product.
Last reviewed:: 2026-09-26

In practice

Dermasift analyses skincare formulations against published cosmetic science. This is information, not medical advice — for a diagnosed skin condition, speak to a dermatologist.

Check this against a product’s ingredient list