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

https://rylansultimatethoughts.talesignal.com/posts/is-standard-hifu-safe-if-done-by-a-non-doctor-operator

Ultherapy targets the deep 4.5 mm SMAS layer using ultrasound, encouraging collagen over 3 to 6 months for natural lift. RF heats skin to 40-45°C for surface tightening but doesn't reach as deep