The ingredient, explained
Hydroxyectoin
-4S,5S--5-hydroxy-2-methyl-3‚4,5‚6-tetrahydropyrimidine-4-carboxylic acid
Ingredient guide
What it is and what it does
About this ingredient: EU CosIng ingredient registry (via Open Beauty Facts taxonomy) ↗
- Emollient
- Helps soften and smooth the skin surface.
- Buffering
- Helps resist changes in a formula's pH.
- Skin conditioning
- A broad cosmetic role for maintaining skin condition. It does not identify a particular clinical benefit.
Function definitions: European Commission ingredient function definitions (SCCNFP/0299/00, pages 16 to 20) ↗
Registry functions describe possible formulation roles, not results for a finished product. A dictionary entry is not an approval or a safety assessment.
A closer look
What the research shows
We have not yet published a checked study for this exact ingredient. This is a gap in our coverage, not a finding that research does not exist or that the ingredient is ineffective.
Ingredient research is not proof that a product containing this ingredient works.
Follow the formula
Products containing this ingredient
From the wider catalogue. Linked by the ingredient list, without an efficacy ranking.
The Procter & Gamble Manufacturing Company
Tula Skincare Protect and Glow Daily Facial Sunscreen Gel SPF 30
Inside the formulaNames and identifiers
- INCI name on ingredient lists
- HYDROXYECTOIN
- CAS registry number
- 165542-15-4
- EC number
- 442-870-8
Sources for this ingredient record
- EU CosIng ingredient registry (via Open Beauty Facts taxonomy) ↗ · ODbL 1.0 (Open Beauty Facts database) · Recorded Aug 8, 2026