Ingredient glossary / Preservative
DMDM hydantoin
On the label: DMDM Hydantoin · Preservative
What it is
A preservative that works by slowly releasing formaldehyde; allowed at low levels, but a known contact allergen for people sensitised to formaldehyde.
Preservatives: Preservatives stop bacteria and mould growing in a product that contains water; every water-based product needs one.
Wikidata: Chemical compound. Q5205613 →
In the research
32 PubMed papers mention it with skin, cosmetics or hair; the three most recent:
- The Prevalence of Contact Allergy to Formaldehyde and Formaldehyde Releasers: A Systematic Review and Meta-Analysis · Contact dermatitis, 2026
- Marked Impact of Regulatory Bans on Formaldehyde and Formaldehyde-Releaser-Induced Allergic Contact Dermatitis: A Retrospective Cohort Study (1996-2024) From Turkey · Contact dermatitis, 2026
- A Cross-Sectional Study of Contact Allergens in Hotel Personal Care Products in Canada, the United States and Europe · Contact dermatitis, 2026
A paper is a paper, not a verdict: titles are listed so you can read them, and a study on cells or mice says little about a cream on a face.
Products whose label lists it
2 on the siteMatched from the ingredient list the supplier printed; the position in the list (first or thirtieth) is on each product page.
Made in the USA
Made in the USAOther preservatives
Dew & Balm describes ingredients from the public record and makes no claim about what a product will do for you. Statements about dietary supplements have not been evaluated by the FDA. If a product causes a reaction, stop using it; a reaction that spreads or affects breathing is a call to a doctor or 911.