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

Noninvasive fat removal is preferred because of decreased downtime and lower perceived risk. It is important to seek new noninvasive fat removal treatments that are both safe and efficacious.

To assess the extent to which carboxytherapy, which is the insufflation of carbon dioxide gas into subcutaneous fat, results in reduction of fat volume.

In this randomized, sham-controlled, split-body study, adults (body mass index, 22-29 kg/m²) were randomized to receive 5 weekly infusions of 1000 cm³ of CO₂ to 1 side of the abdomen, and 5 sham treatments to the contralateral side. The primary outcome measures were ultrasound measurement of fat layer thickness and total circumference before and after treatment.

A total of 16 participants completed the study. Ultrasound measurement indicated less fat volume on the side treated with carboxytherapy 1 week after the last treatment (P = .011), but the lower fat volume 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 change over the entire course of the study (P = 1.00).

Limitations included modest sample size and some sources of error in the measurement of circumference and fat layer.

Carboxytherapy provides a transient decrease in subcutaneous fat that may not persist. Treatment is well tolerated.