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

https://mighty-wiki.win/index.php/Why_Do_Some_People_See_No_Change_After_HIFU%3F

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