Carbon dioxide (CO2) therapy, also known as carboxytherapy, refers to the intradermal and subcutaneous administration of medical CO2 for therapeutic purposes.1,2,3 Carboxytherapy has been used in aesthetic medicine for approximately 20 years for multiple cosmetic indications, such as improving skin quality and treating cellulite, and can be a good treatment to add to your current aesthetic portfolio.1
Understanding CO2 CO2 is an acid oxide that consists of one carbon atom and two oxygen atoms. It is a colourless odourless, inert, noninflammable, water soluble and sterile gas and is considered non-toxic and nonhazardous, except in high concentrations.1 CO2 is heavier than air and, in poorlyventilated spaces, it can reach potentially harmful concentrations (8-15%). To prevent this risk, it is important to use CO2 in wellventilated rooms and to have a log book that demonstrates maintenance and service of the equipment.1
Therapeutic effect of CO2 The first effect following CO2 injection is a strong vasodilation of the vessels; therefore increasing oxygenation in the treated area. It also improves regenerative activities and stimulates the formation of new capillaries – also known as angiogenesis. As a result, it increases circulation and stimulates localised metabolic activity of the tissues, which is known as the Bohr effect.1,4 About 1% of absorbed CO2 converts into carbonic acid CO2+H20=H2CO3; further reacting to leave bicarbonate dissolved in the blood plasma H+HCO3. These reactions cause the pH of the blood to decrease and release oxygen to the tissues.1 As well as this, the trauma caused to the dermis by injection stimulates the body’s own healing process and promotes new collagen synthesis.1,5
Administering CO2 For aesthetic indications, CO2 is injected intradermally and subcutaneously by medical professionals. It involves the use of a device or machine that is connected to
a cylinder of medical CO2. The equipment provides the practitioner with the ability to determine, regulate and monitor the following settings: gas temperature, infusion time, gas flow, volume or dose of gas to be infused, pressure and the volume of gas administrated.6 Only medical CO2 (99.5% v/v min), which has been sourced from a medical supplier and has been quality checked to ensure successful results and maintain patient safety, should be used.6 I obtain mine from BOC group.6 Some companies offer carboxytherapy guns that may come with preloaded cartridges of CO2 and can be used,4 however practitioners must ensure that the gas they use is medical grade by purchasing through a medical supplier. Carboxytherapy can be administered in multiple areas on the face and body in the same session and, from the patient perspective, this is a natural treatment with minimal down time. I tell patients that it’s a treatment that simply gives the body a ‘boost signal’ to switch on its rejuvenating and regenerating activities.
Using CO2 therapy in medical aesthetics In the cosmetic field, carboxytherapy has multiple indications as a stand-alone treatment to treat conditions like cellulite and localised adiposity, stretch marks, skin laxity, skin irregularities, loose skin, dark under-eye circles and eye bags, and scar tissues.4,7,8 Carboxytherapy can also be combined with liposuction surgery as a pre- and postoperative treatment.1,4
To see improvement, around five to 10 sessions are required, depending on the indication.1 Results are not permanent and patients are advised to undergo repeat treatment in six months’ time. Some of the most common aesthetic indications are explored in more detail below, while others are mentioned in Table 1. 1 Carboxytherapy can be used to improve the signs of ageing. A small blind crosssectional pilot animal-based study involving 10 rats found collagen turnover increased in animals following carbon dioxide injection into the subcutaneous cellular tissue and intradermally in comparison with the controls.9 Another larger study observed improvement in skin in animals injected with CO2. It involved 56 rats and suggested that subcutaneous injection of CO2 and atmospheric air decreased the amount of Substance P and pro-Calcitonin GeneRelated Peptide (15 kDa) neuropeptides in rat skin.10 Carboxytherapy can also improve the appearance of the periorbital area, such as dark circles, skin laxity and reduce mild fat pad prolapse.1 It can do this by reducing localised adiposity, stimulating lymphatic
drainage and circulation and oxygenation of the area.1 One study involved 90 patients with moderate to severe periorbital wrinkles and/ or dark circles who underwent subcutaneous injections of CO2 once a week for seven weeks. Two months after the treatment, patients reported a reduction of facial fine lines and wrinkles, as well as a decrease in periorbital hyperpigmentation. Some side effects were observed, but they were transient and did not require discontinuation of treatment.11 In my experience, treatment will not be effective for hereditary or sun damagerelated pigmentation, so these patients should have alternative treatments. Successful treatment of eye bags with CO2 alone is rare and I believe the treatment is more effective when combined with other therapies such as dermal fillers (Figure 2). If combining with fillers in the same area, I will always treat the patient with CO2 first to prevent migration of the injected filler. CO2 may also improve the appearance of cellulite and reduce localised fat deposits such as submental compartments, upper
arm, abdomen and tights.1,4 I have found that the advantage of this treatment is that it is not only reduces fat compartments, but also tightens and rejuvenates skin at the same time. A study by Brandi et al. treated 48 female patients aged 24-51 for localised adipose accumulations, located on the thighs, knees, and/or abdomen.2 Study participants received six sessions of CO2 therapy, two sessions per week. Microscopic results of skin tissues demonstrated a thicker dermis appearance with collagenous fibres and a reduction in cellulite was observed.2 In a clinical audit of an aesthetic practice involving 101 women who underwent CO2 therapy for localised adiposities on the abdomen, it was found that there was a significant reduction in upper, mid, and lower abdomen circumference.12 In the 57 women who underwent thigh therapy, thigh circumference was significantly reduced, respectively, in the right versus left thigh. The authors concluded that results of the audit confirm that carboxytherapy is safe and effective.12 Carboxytherapy for cellulite and fat has its limitations; when treating larger areas like the abdomen or thighs I find that it needs to be combined with physical activities and dietary advice. Surgical methods can give better and longer-lasting results in larger areas. It is important to know that this treatment is only effective in small localised fat compartments.
Treatment tips In my experience of performing carboxytherapy for the past five years, for optimum results, treatment should be combined with a good at-home medical grade skincare routine two to four weeks before in-clinic treatments. The skin must be disinfected and I will usually apply topical anaesthetic for 20-30 minutes to minimise discomfort. For skin rejuvenation, I will use a 30 gauge needle and inject at a 20 degree angle. Intradermal injections will help to improve skin quality, and subdermal injections will help to achieve a lifting effect, as well as reducing any unwanted fat adiposity. My full-face rejuvenation involves 12 strategic injections points; three intradermal injections in the forehead, one intradermal injection into the upper and lower lid, and subdermal and intradermal injection into the zygomatic eminence, nasolabial fold, parotid area, oral commissure, under the angle of mandible, jowls and apex of the chin
When treating eye bags, I insert the needle to a subdermal depth and immediate inflation of the eyelid can be observed. Whilst treating, the patient will experience some warm sensation and very mild pressure when gas is delivered. Following treatment, I apply a skin recovery mask with HA, which has a soothing effect for the patient. CO2 can be effectively combined with other treatments such as PRP, dermaroller, fractional needling, dermal fillers and mesotherapy to address ageing concerns. It should be noted that in more advanced cases where severe sagginess is observed, treatment will not be effective. For treatment of fat pads, injection should be subcutaneous. I use a 30 gauge needle inserted at a 45 degree angle. I find that topical anaesthetic is not required.
Contraindications Relative contraindication need to be taken into consideration when the patient takes anticoagulants, has anaemia, receives therapies with carbonic anhydrase inhibitors or has needle phobia. Absolute contraindications apply if the patient is pregnant or breastfeeding, has acute infection in the treated area, diagnosed with severe heart failure, has acute kidney failure, suffers from neoplasia, acute thrombosis or angina pectoris.1,4
Side effects There is a risk of bruising and mild discomfort in the treated site that can last up to a week post treatment. Mild swelling can last up to 24 hours post treatment and bruising typically will be resolved within seven to 10 days. In the study mentioned above by Brandi et al. very mild side effects were reported, such as crackling under the skin, which resolved within two hours, mild haematomas and mild pain in the treated areas that lasted for a few days post treatment.2 The use of higher concentrations are not recommended as patients may report headaches, and, in more severe cases, vomiting and nausea. There should not be any toxicity if practitioners deliver the correct the amount of gas, as advised by recommended protocols per treated area (Table 1).1 For eye bag treatments, mild puffiness of the eyelids can remain up to 24-48 hours’ post treatment, although I find that in most cases this is just two hours. Note that there is a high risk of post-injection bruising around the periorbital area.
Conclusion Carboxytherapy can be an excellent addition to an aesthetic clinic. In my experience, it has a high safety profile with minimal downtime. This therapy is very appealing
to the category of patients who are looking for more natural therapies and it can be used as a combination treatment with other treatment approaches. As with other treatments, consultation skills need to be applied and patient expectations need to manged correctly. Practitioners should seek appropriate training before introducing into their practice.