The cells in our body are constantly producing carbon dioxide as a waste product. We breathe in oxygen, which is carried by red blood cells to our tissues. When the red blood cells are exposed to high concentrations of carbon dioxide, in areas in our body that have been working hard, they flip their conformation, releasing oxygen molecules and picking up carbon dioxide. This carbon dioxide is then exhaled from our lungs. Carboxytherapy involves injecting small amounts of carbon dioxide just below the surface of the skin, increasing blood circulation. This improves the appearance of dark circles and stretch marks by increasing blood flow in that area.