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

https://www.hometalk.com/member/254051008/alice1337254

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