Common Name(s): Phenylethyl resorcinol,symwhite 377,ultra-potent tyrosinase inhibitor
CAS Number: N/a
DESCRIPTION
What It Does: Inhibits tyrosinase with exceptional potency to reduce melanin synthesis, correct hyperpigmentation and melasma, even skin tone, and prevent uv-induced melanogenesis stimulation โ at concentrations 10โ50ร lower than conventional brightening actives.
Why It's Used: The highest-potency brightening active commercially available with regulatory acceptance โ 50ร greater tyrosinase inhibition than kojic acid at equivalent concentration enables effective brightening at 0.1โ0.5% versus 1โ2% for conventional brighteners.
How It Works: The 1,3-dihydroxybenzene resorcinol core chelates tyrosinase's dinuclear cuยฒโบ active site through the ortho-diol arrangement. the phenylethyl substituent at c4 fills the tyrosinase substrate channel hydrophobic pocket, providing dual-mechanism inhibition: copper chelation + hydrophobic channel occupancy simultaneously. logp ~2.8 provides excellent sc partitioning for melanocyte delivery.
Typically Found In: Premium brightening serums,melasma treatment
TECHNICAL DETAILS
Primary Category: Active ingredient โ antioxidant
Secondary Functions: Free radical scavenging,anti-aging
Application Areas:
Facial Skincare
Body Care
Hair Care
Beard Care
Color Cosmetics (Makeup)
Dietary/Oral Supplements
Typical Concentration Range: 0.1%โ0.5%
SOURCING & ETHICS
Vegan Status: Conditional - supplier confirmation required
Halal Status: Unverified - supplier confirmation required
Source Notes: Plant-derived extract or synthetic. [audit 2026-07-29 rev2: status downgraded on audit. determination requires shariah-panel sign-off.]
SKIN COMPATIBILITY
Irritancy Rating: 1/5 โ very low
Comedogenicity Rating: 0/5 โ non-comedogenic
Sensitivity Concerns: Non-irritating; well-tolerated.
Safe for Sensitive Skin: Yes
SAFETY & COMPATIBILITY
Safety Profile: Excellent safety profile. ewg score: 1.
Works Well With: Vitamin c,vitamin e,ferulic acid,spf,other antioxidants
Avoid Combining With: No significant incompatibilities
SCIENTIFIC NOTE
Phenylethyl resorcinol ic50 4 ฮผm vs kojic acid ic50 200 ฮผm โ 50ร greater molar potency. this efficiency allows effective brightening at concentrations below eu restriction thresholds for many phenolic brighteners, enabling simpler regulatory compliance.
Last Verified: