Undecylenoyl phenylalanine is a lab made molecule built from an amino acid, phenylalanine, attached to a fatty acid derived from castor oil. It works differently from most brightening ingredients by blocking the messenger that tells pigment producing cells to ramp up melanin output in the first place, rather than blocking the pigment making enzyme itself.
In a clinical study, a cream containing this ingredient measurably reduced the appearance of facial hyperpigmentation, and combining it with niacinamide produced an even stronger effect than either ingredient used alone.
Because it works upstream of pigment production, it is often used alongside other brighteners that act through different mechanisms.
Undecylenoyl Phenylalanine References
Reduction in the Appearance of Facial Hyperpigmentation by Topical N-undecyl-10-enoyl-L-phenylalanine and Its Combination with Niacinamide, Journal of Cosmetic Dermatology, 2009
Preparation, Characterization, and Evaluation of Anti-tyrosinase Activity of Solid Lipid Nanoparticles Containing Undecylenoyl Phenylalanine, 2022
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