Imidazolidinyl Urea



No known benefits

Imidazolidinyl Urea description

Preservative considered weaker than its “cousin” diazolidinyl urea. Most often used with parabens because they work well together. Imidazolidinyl urea is considered a formaldehyde-releasing preservative. Although that sounds scary, the amount of formaldehyde released is well below the limits for safe exposure.

Imidazolidinyl Urea references

  • International Journal of Cosmetic Science, October 2015, pages 474-478
  • Skin Pharmacology and Physiology, 2012, pages 236-240

Peer-reviewed, substantiated scientific research is used to assess ingredients in this dictionary. Regulations regarding constraints, permitted concentration levels and availability vary by country and region.

Ingredient ratings


Proven and supported by independent studies. Outstanding active ingredient for most skin types or concerns.


Necessary to improve a formula's texture, stability, or penetration.


Generally non-irritating but may have aesthetic, stability, or other issues that limit its usefulness.


There is a likelihood of irritation. Risk increases when combined with other problematic ingredients.


May cause irritation, inflammation, dryness, etc. May offer benefit in some capability but overall, proven to do more harm than good.


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Not rated

We have not yet rated this ingredient because we have not had a chance to review the research on it.