Subcutaneous infiltration of carbon dioxide (carboxytherapy) for abdominal fat reduction: A randomized clinical trial

Background: Noninvasive fat removal is preferred by patients primarily because there is decreased downtime and lower perceived risk. It is important to seek new noninvasive fat removal treatments that are both safe and efficacious. We aim to assess the extent to which carboxytherapy, the insufflation of carbon dioxide gas into subcutaneous fat, results in reduction of fat volume. Methods: This was a randomized, double-blind, sham-controlled, split-body study. Adult subjects in good health were enrolled and randomized to receive 5 weekly infusions of 1,000 cc CO2 to one side of the abdomen, and 5 sham treatments to the contralateral side. Primary outcome measures were ultrasound measurement of fat layer thickness on treated versus nontreated sides, as well as total circumference before and after treatment. Results: 16 participants completed the study and were analyzed. Ultrasound measurement indicated less fat volume on the sides treated with carboxytherapy 1 week after the last treatment (P =.011), but this difference was not maintained at 28 weeks. Total circumference decreased nominally but not significantly at week 5 compared with baseline (P =.0697). Participant body weights did not significantly change over the entire course of the study (P = 1.00). Conclusion: Carboxytherapy provides a transient decrease in subcutaneous fat that may not persist. Treatment is well tolerated.