The materials

When using carboxytherapy as a treatment for cellulite or sagging skin, a number of materials are essential:

  • A bottle of sterile medical CO2
  • A gas expander mechanism for diffusion of the gas with a constant pressure of a few atmospheres
  • A gun diffusion system to control the exact amount of gas injected
  • A filter for output of the regulator, which can be changed every three or four sessions
  • Disposable tubing connected to the filter and a needle
  • A single-use pattern to dampen the sting
  • Needles 27–32G depending on the area, volume and the desired depth of treatment.

The gun can be programmed according to the type of treatment carried out, and the gas flow will be issued depending on the diameter of the needle (usually 30G), the amount of CO2 released (1–100 cm3), and depth of injection (3–5 mm for cellulite and 2–3 mm for sagging skin). The management of gas delivery is electronic. The flow is directly connected to the diameter of the needle used:

  • 25G = 195 ml/mn
  • 27G = 150 ml/mn
  • 30G = 65 ml/mn
  • 32G = 25 ml/mn.

Sometimes it might be necessary to change the needle during the treatment session as it can dull.

Treatment protocol

The treatment involves a series of 10–15 sessions, which can be varied depending on the indications and outcomes sought. The patient will usually have one or two sessions per week. To sustain the results, the author recommends offering bi-annual follow-up. The gas–tissue interface is paramount, with at least 20 minutes per zone.

Purge the tubing/pipes

When the pipes still contain some air following a poor purge, the air injected under the skin can cause temporary inflammation.

Injection depth

The injection of gas is only triggered when the needle has reached the desired depth. The injection should be as superficial as possible during certain indications, such as the treatment of sagging skin, and deeper in the treatment of cellulite. The limiting factor will be pain owing to gas expansion; the more superficial the injection, the greater the pain. Injections into the deep dermis or subcutis are much less painful.

Amount to inject

The amount of gas to inject depends on the area to be treated and the patient’s tolerance. The gas diffuses slower and with greater difficulty during the first few sessions; however, it spreads much more easily in larger quantities and after the relaxation of deep tissues.

Number and frequency of treatment sessions

It is paramount not to exceed the threshold of pain for each indication. The parameters will be adjusted according to each subject, but general protocols can be followed for each area:

  • The face, arms or legs: 10–15 sessions, 300–400 cm3
  • Cellulite: it is good to induce a process of lipolysis in as few sessions as possible; e.g. two per week for 3 weeks followed by one session per week until a good result is achieved. On average, 10–12 sessions with 100–300 cm3 per zone.

Injections are made to the dermis or subcutaneous tissue depending on indication

It is important to cover the entire surface to be treated during the sessions. The treatment area can be palpated to assess the diffusion of the gas as it takes very precise routes and does not necessarily cover the entire treatment area.

The gas must be injected slowly to reduce the sensation of pain and it is imperative that the area is in emphysema for 20 minutes. The resorption of the gas is very quick at the beginning of the session, and then after some flux, the resorption will be slower. It is paramount to note that all areas are well swollen with the gas for 20 minutes.

Residual erythema is a good indicator of distribution and is indicated by the vasodilatation. It is important to identify the effect on the diffusion zones effect. When an area is well perfused by the gas, there is an erythema. If the gas is ineffective, the skin will show no erythema, so more CO2 will need to be injected.


After injection, there is usually swelling, erythema, and warmth for a few minutes. However, it is possible for the patient to continue with his/her daily activities. According to their own sensitivity and the areas of injection, patients may feel some tingling, biting or burning sensations that are usually more annoying than painful. The physician should therefore ask the patient to report on any side‑effects during and after treatment in order to adjust the various parameters of the device, minimise these unpleasant problems, and make the session as comfortable as possible.

Some patients may also complain of hot flashes, chills, or a feeling of heaviness during injection. These problems dissipate shortly after injection, and are caused by vasodilation and increased blood flow. The author has also noted the appearance (in approximately 15% of treatments) of small bruises at the point of puncture, which also disappear after a few days.

The blood can absorb up to 210 ml of CO2 so it is important to take the time to get the desired amount and remain below this standard.

Infectious risks are minimised by the use of a sterile medical grade gas, the use of particulate filter to the output of the gas tubing, and a sterile disposable needle. The only risk would be nosocomial. CO2 is a natural gas produced by the body, so there is no risk of allergy. It has no toxicity and is discharged through the lungs (for example, during intense exercise the body produces five to 10 times more CO2 that is injected during a session carboxytherapy).


There are a number of contraindications to this type of treatment: recent myocardial infarction, hypertension, recent phlebitis, epilepsy, skin infections of the areas to be treated, use of anticoagulants, or carrying a clotting disorder, pregnancy, renal and respiratory failure, and active cancer.


Carboxytherapy is a relatively new treatment option, but as a result of technological advances it enjoys a great popularity, not least owing to the absence of harm. In addition, carboxytherapy is non-toxic and allergy safe, inexpensive and although it is most effective with a combination of radiofrequency or ultrasound (depending on the indication), it does not necessarily require adjuvant treatment to get good results. It is essential in the range of treatments to offer for beautiful legs.