High-Intensity Focused Ultrasound and Radiofrequency in Non-Invasive Skin Rejuvenation: Mechanisms, Clinical Evidence, and Combined Therapeutic Approaches

Skin aging is a multifactorial process involving structural and functional changes in the dermis. In recent years, the treatment of age-related skin changes in the face, neck, and décolleté has become a growing focus in the fields of esthetic medicine and dermatology. The increasing demand for natural, youthful results without surgical intervention or prolonged downtime has led to the development and widespread application of minimally invasive energy-based technologies, such as High-Intensity Focused Ultrasound (HIFU) and Radiofrequency (RF). The aim of this review is to summarize current evidence regarding the mechanisms of action, clinical efficacy, and safety of HIFU and RF, as well as their combined applications in skin rejuvenation. Relevant studies were selected based on their scientific quality and relevance to the topic. Current evidence indicates that both HIFU and RF promote collagen remodeling and dermal tightening through different energy-delivery mechanisms. Comparative studies suggest that their combined use may enhance esthetic outcomes and improve patient satisfaction. Overall, these technologies represent innovative, non-surgical approaches for facial, neck, and décolleté rejuvenation.