Monopolar Radiofrequency for Facial Hyperpigmentation Treatment: An Integrated Retrospective Clinical Trial and Ex Vivo Study.

Aging-associated facial hyperpigmentation is driven not only by enhanced melanogenesis but also by dermal senescence and deterioration of the dermal-epidermal junction. The purpose of this study was to evaluate whether monopolar radiofrequency (MRF) monotherapy can improve aging-related facial hyperpigmentation by simultaneously suppressing melanogenic signaling and restoring senescence-associated dermal alterations. We assumed that deep dermal heating induced by MRF would modulate fibroblast senescence and basement membrane integrity, thereby indirectly regulating melanocyte activity. In a retrospective review of 26 Asian women, MRF treatment significantly decreased multiple pigmentation parameters, including melanin level, hyperconcentration, and Hemi Melasma Area and Severity Index (hemi-MASI) scores, while concurrently reducing wrinkles, pores, and enhanced overall skin texture without inducing inflammation. Complementary ex vivo experiments using ultraviolet B (UVB)-irradiated human skin demonstrated that MRF markedly reduced pro-melanogenic markers ( α-MSH , MC1R , MITF , TYR , TRP1/2 ), restored collagen type IV expression at the basement membrane, decreased senescence-associated genes ( p16 , p21 ), and upregulated protective heat shock proteins ( HSP70/47 ). Together, these findings suggest that MRF improves aging-associated hyperpigmentation by both suppressing melanogenesis and rejuvenating the senescent dermal microenvironment. MRF may serve as an effective non-invasive treatment option for pigmentation disorders in aging skin.