Urocanic Acid
AKA “104-98-3, Urocaninic acid, 3-(1H-Imidazol-4-yl)-2-propenoic acid, (2E)-3-(1H-imidazol-4-yl)prop-2-enoic acid, 2-Propenoic acid, 3-(1H-imidazol-4-yl)-, G8D26XJJ3B, NSC-66357, (E)-, CHEBI:27248
Acid
Ingredient Facts
Urocanic acid
AKA: 104-98-3, Urocaninic acid, 3-(1H-Imidazol-4-yl)-2-propenoic acid, (2E)-3-(1H-imidazol-4-yl)prop-2-enoic acid, 2-Propenoic acid, 3-(1H-imidazol-4-yl)-, G8D26XJJ3B, NSC-66357, (E)-, CHEBI:27248
Acid · Uv Absorber · EWG: 3
Synthetic
Sunscreen Filter
Amino Acid
Acid
Not Clean
2-Propenoic acid, 3-(1H-imidazol-4-yl)-
Solubility 1500
Formula
C6H6N2O2
Mol. Weight
138.12
CAS #
104-98-3
Form
Liquid
State
Solid
See origin →
Functions
Uv Absorber
Blocks or absorbs UV rays to protect your skin from sun damage, dark spots, and premature aging.
Shields from UV damage
Traditional Use
A naturally occurring compound in human skin discovered in the early 20th century. Found to regulate skin pH and provide UV protection; later synthesized and incorporated into modern skincare formulations.
Skin Types
all-skin-types
Best For
Sun Damage
Pregnancy & Breastfeeding Safe
Yes
EWG
3
CIR
Insufficient data
Pregnancy
Yes
CIR Safety Findings
all-shades-safe
Potential Sensitizer
Regulatory Status
USAunder review
EUpermitted
JAPANpermitted
CANADApermitted
Verified Jun 2026
Data: PubChem · CosIng · EWG · CIR