DMDM Hydantoin
Korean INCI: 디엠디엠하이단토인 · Also written as: DMDM
Irritant / cautionMay irritate
What it is
Formaldehyde-releasing preservative
How it affects the score
Flagged separately in results for potential irritation or allergy.
How to read it on the label
If you have a sensitive scalp, avoid products where this sits high on the list.
Ingredients are listed by descending concentration. Anything after the ~1% anchors (EDTA, hexanediol, preservatives) is effectively trace.
Check your own shampoo
Paste your full ingredient list to see this ingredient's position and the overall score.
Related ingredients
Gluconolactone · Base
Glyceryl Caprylate · Base
Dehydroacetic Acid · Base
Diazolidinyl Urea · Irritant / caution
Levulinic Acid · Base
Methylisothiazolinone · Irritant / caution
※ For reference only, based on public ingredient data — not medical advice.