Physicians refer to Ultherapy as color-blind. It does not pose a risk for hyperpigmentation nor worsening melasma in general. There have been however, extremely rarely reported burns with Ultherapy which may have to do with unlicensed providers, knock-off machines, lack of use of ultrasound gel on the skin or improper contact with the skin, or other unknown factors. Should a burn occur, then there is a chance of getting hyperpigmentation which usually is temporary. Without complications, Ultherapy may be used over melasma, but I would avoid the 1.5 mm. shallow transducer as it is normal for welts to occur with this one (not the 3mm. and 4.5mm. deeper transducers). The welts from the 1.5mm. transducer go away as quickly as a few hours to a couple of days in some patients to several weeks in others. I would not want to induce welts in melasma skin, so I limit treatment with Ultherapy on melasma skin, and in skin that is prone to postinflammatory hyperpigmentation to the 3mm. and 4.5mm. transducers.If I need the more superficial energy I can use ThermiSmooth radiofrequency for skin tightening which also is color blind and welts are not created.The information provided in Dr. Shelton's answer is for educational purposes only and is not intended to constitute medical advice. The information provided should not be relied upon as a substitute for consultations with a qualified health professional who may be familiar with your individual medical needs.