It might be wise to wait six months or more after CO2 laser before Ultherapy but CO2 can be done soon after ultherapy, possibly even the same day, especially if it is fractional CO2. However, as Ultheapy has developed a more superficial transducer, this will treat the same plane of dermis as the CO2 laser and although the Ultherapy does not create an open wound, until it is researched further, there might be an affect on the dermis from the Ultherapy that could interfere with the healing of the CO2 laser. On the other hand, scientific studies may reveal conclusions that were not expected and it might be found that the ultherapy stimulates new collagen and blood flow that could help healing. The optimum time between treatments has not been studied and you need to discuss your treatment regimen in detail with your doctor.