Ultherapy uses focused ultrasound to target the deep 4.5 mm SMAS layer,...

https://www.bookmarking-base.win/ultherapy-targets-the-deeper-4-5-mm-smas-layer-using-focused-ultrasound

Ultherapy uses focused ultrasound to target the deep 4.5 mm SMAS layer, encouraging natural collagen over 3 to 6 months for gradual lifting. Compared to RF, which heats skin surface to around 40-45°C, it's deeper but less immediate