Common Name(s): 3-(1h-imidazol-4-yl)acrylic acid,uca,filaggrin breakdown product
CAS Number: 104-98-3
DESCRIPTION
What It Does: Provides uv-absorbing nmf protection and humectancy from filaggrin-derived urocanic acid.
Why It's Used: Uv-protective nmf component depleted in eczema — urocanic acid replenishment addresses both the uv protection deficit and nmf humectancy loss characteristic of filaggrin mutation eczema skin.
How It Works: Trans-urocanic acid absorbs uv-b (270–310nm) acting as natural sunscreen component. cis-isomer formed by uv irradiation has immunomodulatory effects. nmf component providing hydration. formed from histidine by filaggrin-encoded urocanase enzyme during cornification.
Typically Found In: Eczema barrier repair,uv-protective products
TECHNICAL DETAILS
Primary Category: Active ingredient – uv-absorbing nmf component
Secondary Functions: Skin conditioning
Application Areas:
Facial Skincare
Body Care
Hair Care
Beard Care
Color Cosmetics (Makeup)
Dietary/Oral Supplements
Typical Concentration Range: 0.1%–3%
SOURCING & ETHICS
Vegan Status: Conditional - supplier confirmation required
Halal Status: Unverified - supplier confirmation required
Source Notes: Commercially produced for cosmetic use. verify vegan/halal status with supplier. [audit 2026-07-29 rev2: the record's own source_notes does not assert a non-animal origin, or instructs the reader to verify with the supplier; "yes" asserts knowledge the record does not hold. determination requires shariah-panel sign-off.]
SKIN COMPATIBILITY
Irritancy Rating: 1/5 – very low
Comedogenicity Rating: 0/5 – non-comedogenic
Sensitivity Concerns: Well-tolerated by most skin types.
Safe for Sensitive Skin: Yes
SAFETY & COMPATIBILITY
Safety Profile: Good safety profile at recommended concentrations. ewg score: 1–2.
Works Well With: Standard skincare actives
Avoid Combining With: No known significant incompatibilities
SCIENTIFIC NOTE
Urocanic acid's absence in atopic dermatitis skin (due to filaggrin gene mutations preventing its biosynthesis) contributes to both the uv sensitivity and the impaired barrier hydration of eczema. the same filaggrin mutation that causes urocanic acid deficiency also reduces nmf amino acid production from filaggrin proteolysis — a single gene defect causing multiple simultaneous nmf component deficits.
Last Verified: 2026-03-12
Primary Sources: Cosing database,brown et al. filaggrin urocanic acid study