Ingredient glossary

DMDM Hydantoin

INCI: DMDM Hydantoin · Also: Glydant

Quietly necessary

A preservative doing an unglamorous but essential job: keeping the product safe to use. Not something you pay extra for.

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What it does

  • preservation

strong evidenceSafety reviews and patch test data indicate DMDM hydantoin at cosmetic use levels is generally safe for non allergic users but eight to nine percent of the population with formaldehyde allergy may react to products containing it or related releasers.

On a label: usually effective at 0.2-0.6%.

Who it's for, and who should skip it

Tends to suit

  • all

Approach with care

  • formaldehyde allergy
  • very sensitive
  • Clogs poresLow
  • Irritation riskModerate

Pregnancy: Check with your doctor before using during pregnancy or breastfeeding.

Plays well with

  • other preservatives

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Educational information about a cosmetic ingredient, not medical advice.