Combining High-Intensity Focused Ultrasound and Monopolar Radiofrequency: A Multilayer Strategy for Improved Facial Rejuvenation

High-intensity focused ultrasound (HIFU) and monopolar radiofrequency (RF) are widely used noninvasive modalities for facial tightening and rejuvenation. Although both technologies induce thermally mediated collagen remodeling, they differ in their mechanisms of energy delivery and patterns of tissue heating. HIFU produces focal thermal coagulation at predetermined tissue depths, enabling selective structural contraction and lifting, whereas monopolar RF generates broader volumetric heating within the dermis and subcutaneous tissue, contributing to diffuse tightening and improvements in skin quality. Because facial aging is a multilayer process involving the skin, subcutaneous tissue, and supporting structures, combining these modalities may provide a more comprehensive approach than either treatment alone. This article discusses the biological and clinical rationale for combined HIFU and monopolar RF treatment, with emphasis on complementary tissue targeting, treatment sequencing, individualized energy delivery, and safety considerations. Particular attention is given to avoiding excessive cumulative thermal exposure and preserving facial volume in anatomically thin or sensitive regions. Although clinical experience and existing histologic evidence support the concept of complementary and potentially additive effects, the superiority of combination treatment over either modality alone has not yet been established Further controlled studies using standardized objective and patient-reported outcomes are needed to determine whether this multilayer strategy results in superior and durable clinical outcomes.