Ultherapy uses ultrasound energy targeting the 4.5 mm SMAS layer to stimulate...

https://hectorsmasterinsight.novacrestiq.com/posts/how-many-ultherapy-treatments-have-been-done-worldwide-unpacking-the-global-track-record

Ultherapy uses ultrasound energy targeting the 4.5 mm SMAS layer to stimulate collagen deep under the skin, with results peaking around 3 to 6 months