A Systematic Review of High-Intensity Focused Ultrasound in Skin Tightening and Body Contouring.

High-intensity focused ultrasound (HIFU) has emerged as a noninvasive technology for aesthetic applications, offering skin tightening, facial rejuvenation, and body contouring. This systematic review assesses its clinical efficacy, safety profile, patient satisfaction, and future advancements. A comprehensive search of studies published between January 2010 and October 2024 identified 45 clinical trials and cohort studies meeting inclusion criteria, which focused on measurable outcomes, such as wrinkle improvement and circumference reduction. HIFU demonstrated significant efficacy in skin tightening, particularly in the lower face, neck, and periorbital regions, with improvements in skin laxity ranging from 18% to 30%. For body contouring, studies documented a reduction in circumference between 2.5 and 4.5 cm, notably in the abdomen and thighs. Compared with mild surgical outcomes, HIFU provided effective noninvasive lifting with a favorable safety profile; fewer than 5% of patients reported transient erythema, swelling, or mild discomfort. Advances in HIFU technology, such as parallel-beam ultrasound, have improved treatment precision and patient comfort. Although HIFU has demonstrated consistent results across different anatomical areas, standardization of treatment protocols remains a key challenge, particularly regarding optimal energy settings and patient selection criteria. Additionally, further research is needed to establish its long-term efficacy and explore its applications across diverse skin types. HIFU continues to be a promising alternative to surgical interventions, enhancing skin rejuvenation and body contouring with minimal downtime. Future investigations should focus on refining treatment protocols and integrating emerging technologies to optimize clinical outcomes. Level of Evidence: 3 (Therapeutic).