Background Irregular skin pigmentation may be a substantial contributor to the signs of aging and to a person's lack of psychological well-being. Although a large number of skin-lightening agents are available, the opportunity exists to identify more efficacious agents, agents that target alternative biological mechanisms. Aims To provide clinical evidence of the skin-lightening effect of the tetrapeptide, Pro-Lys-Glu-Lys (PKEK), on subjects with skin types V-VI living in South Africa. Methods Pro-Lys-Glu-Lys was evaluated in a double-blind and vehicle-controlled clinical study using expert grading of digital images by comparing its effects in subjects with skin types V-VI suffering from facial melasma and postinflammatory hyperpigmentation. Results This study demonstrated the efficacy of PKEK on subjects with skin types V-VI. On comparing the two treatments, the skin-lightening peptide-containing formulation was significantly superior to the vehicle at 12weeks on overall appearance (P<0.05) and evenness of skin tone (P<0.01). Conclusions The tetrapeptide, PKEK, has proven skin-lightening benefits on skin discoloration from melasma and postinflammatory hyperpigmentation. These studies have been conducted on subjects with skin types V-VI living in South Africa, but we believe this technology to be suitable for all racial groups.
- Proline attached to its N-terminus
- α-melanocyte-stimulating hormone