Ulthera/Ultherapy and Fraxel cannot truly be compared to one another.
Fraxel is a more of a superficial skin tightening treatment while Ultherapy goes deeper to stimulate while it sends ultrasound energy to the dermis and muscle tissue of the face to cause lifting and thus tightening.
Fraxel is a procedure that works on the upper epidermis down. Fraxel works on upper skin issues such as breaking up the pigmentation and then having it slough off a few days later.
Stimulation from the heat it helps promotes collagen growth and also provides a firming of the skin itself.
Because the skin is being exfoliated deeply with Fraxel, fine lines are smoothed.
Ultherapy does not exfoliate, and although it also stimulates collagen , the treatment goes deep to the muscle and helps the muscle contract, thus lifting and firming
With Ultherapy the results can be instant, and continued results happen over the next 6 months post treatment.
Both treatment can be combined (not as a same day treatment) to provide awesome results.