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

https://www.mediafire.com/file/et59n4ewy7unyct/pdf-24805-21355.pdf/file

Ultherapy uses focused ultrasound to target the 4.5 mm SMAS layer, reaching deeper than standard HIFU, which works around 1.5 mm. RF heats skin to 40-45°C to stimulate collagen more superficially