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

https://www.booknose.win/ultherapy-uses-focused-ultrasound-targeting-the-4-5-mm-smas-layer-for-natural-1

Ultherapy uses focused ultrasound to target the 4.5 mm SMAS layer, stimulating collagen deep beneath the skin. It typically takes 3 to 6 months to see peak results