A double-blind vehicle-controlled study of a preparation containing undecylenoyl phenylalanine 2% in the treatment of melasma in females

Background: Undecylenoyl phenylalanine is a novel skin-lightening agent, probably acting as α-melanocyte-stimulating hormone (α-MSH) and beta-adrenergic receptor (β-ADR) antagonist.

Objectives: The objective of this double-blind randomized comparative study was to evaluate the efficacy and safety of a preparation containing undecylenoyl phenylalanine 2% in the topical treatment of melasma in females.

Methods: Forty female patients with melasma were randomly assigned to apply either the active preparation or the vehicle alone, twice daily for 12 weeks. Patients were evaluated monthly for efficacy and safety.

Results: In all, 37 patients completed the study. Of the 20 patients on active treatment, no one responded completely, but 17 (85%) had partial response. Of them, 11 had moderate improvement and six had marked improvement. Lightening of the lesions was evident from the first follow-up visit at 4 weeks. A statistically significant difference (P < 0.001) in efficacy between the active preparation and the vehicle was documented. Using patient assessment ratings, 80% were extremely satisfied or satisfied with the result. The reported side effects were minor and included erythema and itching or burning at the site of application.

Conclusions: Undecylenoyl phenylalanine 2% achieved a significant lightening of melasma lesions with minimal side effects.

melanogenesis; melasma; topical treatment; undecylenoyl phenylalanine; α-melanocyte-stimulating hormone; β-adrenergic receptors.