Once the cells in the targeted area reach a certain temperature, they experience cellular damage. While this may seem counterintuitive, the damage actually stimulates the cells to produce more collagen — a protein that provides structure to the skin. The increase in collagen results in tighter, firmer skinTrusted Source with fewer wrinkles. Since the high-frequency ultrasound beams are focused on a specific tissue site below the skin’s surface, there’s no damage to the upper layers of the skin and adjacent issue.

HIFU may not be appropriate for everyone. In general, the procedure works best on people older than 30 with mild-to-moderate skin laxity. People with photodamaged skin or a high degree of loose skin may need several treatments before seeing results.