Poor blood circulation is partially responsible for cellulite and stretch marks. Cells in the body release carbon dioxide as waste. Red blood cells take the oxygen you inhale and carry it to tissues, then pick up carbon dioxide. Eventually, the carbon dioxide is exhaled by the lungs. When carboxytherapy is used to treat stretch marks and scars, it’s relatively painless. This is because scar tissue doesn’t have nerves. You may feel an itching sensation as the stretch marks are distended during the procedure. The itchiness should resolve in about five minutes.