Ultherapy targets the deep 4.5 mm SMAS layer using ultrasound energy,...

https://bizzmarkblog.com/is-ultherapy-fda-cleared-for-lifting-or-just-tightening/

Ultherapy targets the deep 4.5 mm SMAS layer using ultrasound energy, stimulating collagen over 3 to 6 months for gradual lifting. Compared to RF, which heats skin to 40-45°C mainly for surface tightening, Ultherapy offers deeper lift