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

https://scarlettssuperbnews.inkharbory.com/posts/ultherapy-vs-standard-hifu-what-did-the-2024-study-say

Ultherapy uses focused ultrasound to target the 4.5 mm SMAS layer, stimulating collagen deep under the skin for gradual tightening. It’s known for visible improvements over 3 to 6 months