Is Carboxytherapy Safe? Why CO₂ Does Not Mean Risk-Free

Have you heard that carboxytherapy uses “ordinary carbon dioxide” and therefore assumed it must be almost risk-free? The fact that a procedure uses CO₂ does not, on its own, make it safe. With injectable carboxytherapy, a needle introduces gas into or under the skin: injection depth, body area, gas delivery, sterility, your health and the practitioner’s skill all matter. Small clinical studies describe temporary pain, swelling, redness and bruising; reports of rare severe complications also come from individual case descriptions. These different sources do not allow a precise calculation of risk. Long-term safety has not been adequately studied for the various cosmetic protocols, so “safe for everyone” would be misleading.

First clarify: injections or a topical mask?

“Carboxytherapy” can mean different things in beauty settings. The injectable technique punctures the skin to introduce medical carbon dioxide. Other offerings are gels, masks or topical products applied without needles. They differ in how ingredients reach tissue, what might go wrong, and how much evidence is available. Injection studies cannot automatically prove that “needle-free CO₂ care” is safe or effective, nor can evidence on a mask validate injections. A CO₂ laser is different again: it works with light, not injected carbon dioxide, despite its similar name.

What side effects are actually known?

During gas introduction, patients may feel pressure, stretching, stinging or pain; sensations depend on the site and technical parameters. Temporary swelling, redness, tenderness and bruising are reported more often than serious problems. Around the eyes, even moderate swelling may be obvious in photographs or video calls. On the body, tissue tightness or tenderness near the punctures can interfere with comfort. Nobody can promise that all visible signs will vanish by the next morning.

Medical case reports describe uncommon subcutaneous emphysema, meaning gas spreads through tissues beyond the intended area, including after treatments on the body and around the eyes. Soft-tissue infections have also been reported when equipment-cleaning practices failed. These events do not happen to everyone and the available heterogeneous studies do not establish a reliable individual incidence rate. They do explain why technique and infection control matter as much as the identity of the gas.

When should you cancel or seek a medical assessment first?

An injectable procedure should not be performed through inflamed, damaged or infected skin without medical evaluation. Fever, significant infection, clotting disorders, blood-thinning medicines, or serious cardiovascular, respiratory or kidney disease call for an individual medical decision, not an automatic approval based on a form. Reviews of carboxytherapy also mention thrombosis, severe vascular conditions and uncontrolled high blood pressure as reasons for caution, although these lists are not equally validated instructions for every machine. Because good safety data are lacking, elective injections are best deferred during pregnancy or breastfeeding.

Tell the clinician about previous operations or injections in the area, healing difficulties, diabetes, reactions to skin-preparation products, and a tendency to keloid scarring. If your concern is under-eye darkness, find out whether pigment, visible vessels, an anatomical shadow or swelling is responsible. These four causes require different approaches; injecting gas will not automatically resolve all of them.

How do you distinguish an ordinary reaction from a warning sign?

Do not try to squeeze out gas, vigorously massage a swollen area or inject anything yourself. No universal home remedy has been shown to rule out complications after CO₂ injections.

Has long-term safety been demonstrated?

A systematic review published in 2025, searching literature up to July 2023, included 41 publications on different uses of injectable carboxytherapy and identified promise in some areas, but did not establish the long-term safety of every protocol. “Promising” does not mean large multi-year trials with standardised dosing and reliable detection of uncommon harms. Small studies and differing protocols leave gaps: some examined under-eye skin, others scars, cellulite or local fat. Risks of an injection in the thigh should not automatically be assumed identical to those near the lower eyelid. Finding no serious reaction in a few dozen participants does not show that a rare reaction is impossible.

Balance the expected benefit against the inconvenience and expense of repeated appointments. In one small randomised comparison for under-eye dark circles, fractional CO₂ laser treatment performed better than carboxytherapy on some participant assessments, although both methods had adverse effects. That does not prove laser treatment is safer for everyone: its recovery is different and suitability depends on skin and the cause of the circles. Choose only after identifying what causes the concern, rather than relying on a generic promise to “increase oxygen in the skin.”

What will recovery look like when you need to see people?

Many patients can resume quiet daily activities after injections, but social visibility depends on the treated area. The face, especially under the eyes, may look puffy. On the body, clothing can cover bruises, although tenderness may interfere with exercise. How long these signs last varies. Avoid scheduling a first session immediately before a wedding, major photoshoot or trip if several days of unpredictable appearance would be stressful. Ask when makeup, workouts, sauna and sun exposure are appropriate after your precise technique; mask aftercare is not injection aftercare.

Before your first visit, ask which device and gas are used, why this method is suggested for your particular concern, how the skin and disposable parts are prepared, who injects and what medical training they have. Ask which harms are actively monitored, where complications can be assessed, what would make the team stop a treatment course, and how progress is documented. “CO₂ is natural, so allergies are impossible” is not adequate information for informed consent.

Is there a lower-risk route?

Sometimes that is not having injections. For sensitive skin or modest cosmetic concerns, established skin care or treatment of an identified dermatological problem may be a better starting point. Scars, pigmentation and under-eye puffiness call for different choices after diagnosis; compare realistic benefit and harm for the precise issue you have. No one needs carboxytherapy as routine maintenance. When the potential benefit is unclear and the inconvenience or restrictions matter to you, declining now is every bit as reasonable as consenting after discussion.