Ultherapy uses focused ultrasound targeting the 4.5 mm SMAS layer, unlike RF...

https://technivorz.com/why-is-imaging-such-a-big-deal-in-ultrasound-skin-tightening/

Ultherapy uses focused ultrasound targeting the 4.5 mm SMAS layer, unlike RF which heats skin to 40-45°C for collagen boost. Standard HIFU often treats shallower layers. Thread lifts offer immediate lift but may carry more downtime