The first time I heard about carboxy therapy, I didn't know what it was either. Actually, carboxy therapy is when a nurse, or a physician's assistant, injects your fat with carbon dioxide. The theory behind it is that if you inject your fat with carbon dioxide, what's the body going to do in response? Send more oxygen to the area. If we increase your circulation where your fat is, it's going to become healthier, less stagnate. You're going to move toxins away and water waste away. You'll eventually reduce the cellulite, or the appearance of such, in that area.
The problem is carboxy therapy doesn't really work. I know people who've done it. I've seen the results of it. I think you'd have to do carboxy therapy in your problem area for years before you'd see a real promising result.
My advice? Go to the gym more, drink more water, and have a green juice instead. I hope that helps you decide about carboxy therapy.