Common Name(s): Sepiwhite msh,n-undecylenoyl-l-phenylalanine
CAS Number: 175357-18-3
DESCRIPTION
What It Does: Prevents melanocyte activation by alpha-msh signaling – a pre-enzymatic brightening mechanism distinct from all tyrosinase inhibitors.
Why It's Used: Unique brightening mechanism targeting mc1 receptor upstream of tyrosinase – the only common brightener targeting melanocyte activation rather than melanin synthesis, providing complementary synergistic activity with tyrosinase inhibitors.
How It Works: Competes with alpha-msh for binding to mc1 receptor on melanocytes. prevents receptor activation, reducing camp accumulation and creb-mediated mitf transcription factor upregulation, blocking the entire downstream cascade before tyrosinase expression.
Typically Found In: Brightening serums,uv-darkening prevention,melasma products
TECHNICAL DETAILS
Primary Category: Active ingredient – msh receptor modulator
Secondary Functions: Msh receptor competition,pre-enzymatic brightening,uv darkening prevention
Application Areas:
Facial Skincare
Body Care
Hair Care
Beard Care
Color Cosmetics (Makeup)
Dietary/Oral Supplements
Typical Concentration Range: 2%–5%
SOURCING & ETHICS
Vegan Status: Yes – synthetic
Halal Status: Yes
Source Notes: Synthetic or plant-derived.
SKIN COMPATIBILITY
Irritancy Rating: 1/5 – very low
Comedogenicity Rating: 0/5 – non-comedogenic
Sensitivity Concerns: Non-irritating; well-tolerated.
Safe for Sensitive Skin: Yes
SAFETY & COMPATIBILITY
Safety Profile: Excellent safety profile. use with spf for maximum efficacy. ewg score: 1.
Works Well With: Niacinamide,vitamin c,alpha-arbutin,tranexamic acid,spf
Avoid Combining With: No significant incompatibilities
SCIENTIFIC NOTE
Sepiwhite msh's mc1 receptor competitive antagonism targets the very first step of uv-induced melanogenesis – before any enzymatic step, mitf transcription, or tyrosinase expression. this upstream blockade potentially provides better uv-darkening prevention than tyrosinase inhibitors that act only after melanocyte activation has already occurred.
Last Verified: 2026-03-12
Primary Sources: Cosing database,grimes et al. undecylenoyl phenylalanine study,seppic technical data