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

https://touch-wiki.win/index.php/What_Are_Ultherapy_%27Lines%27_and_Why_Do_They_Matter%3F

Ultherapy uses focused ultrasound to target the 4.5mm SMAS layer, stimulating collagen for gradual tightening over 3 to 6 months. Compared to RF, which heats skin to 40-45°C for surface collagen boost, Ultherapy dives deeper