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

https://xeon-wiki.win/index.php/Does_Ultherapy_Hurt_and_What_Affects_Comfort%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