Mofettes
CO₂ dry bath
Heart & circulation
Mofettes — natural CO₂ dry baths that stimulate skin circulation.
By the Terra Cura editorial team · Last updated: August 2026
Health notice
This article offers editorial health and travel information and is no substitute for medical advice, diagnosis or treatment. Heart and circulatory conditions must be assessed and monitored by a doctor — never change or stop your medication for a cure, and always seek medical clearance before mofette therapy.
What is it?
Peripheral circulatory disorders, mild hypertension and convalescence after illness affect many people. A gentle stimulation of the circulation can support recovery.
In the volcanic regions of the Eastern Carpathians, natural carbon dioxide — a legacy of the area's recent volcanism — escapes from the ground and collects in special basins. In mofettes (dry CO₂ baths) this gas is remarkably pure, around 95–98% carbon dioxide, and it has been used for heart and circulation cures for generations. Covasna even hosts a dedicated cardiovascular rehabilitation hospital built around the therapy.
How Romania's spas help
Traditionally recommended are:
- Mofettes (CO₂ dry baths) — natural carbon dioxide from the ground
- Stimulation of skin circulation — CO₂ has a vessel-widening effect through the skin
- Mild CO₂-rich mineral waters — as an accompaniment to the cure
- Quiet mountain resorts — a gentle climate for convalescence
Well-known Romanian mofette resorts include Covasna, Băile Tușnad and Balvanyos. Learn more about the remedy on our page Remedy: Mofettes.
How the natural remedy is thought to work
The trick is that carbon dioxide is a small, fat-soluble molecule, so it passes through intact skin even in a dry gas bath — no water needed. Once absorbed, it acts on the small vessels near the skin surface and makes them widen (vasodilation). Skin blood flow rises, the skin reddens and feels pleasantly warm, and this peripheral opening can gently ease the load on the heart, nudging heart rate and blood pressure downward. In water-based carbonated (carbogaseous) baths, as offered at classic mineral-water resorts, the same principle is used to support the circulation. Laboratory work also suggests CO₂-rich bathing can encourage the growth of collateral blood vessels in poorly perfused limbs.
Safety by design: because carbon dioxide is heavier than air, it pools at floor level in the mofette basin. Guests stand so the gas reaches only the lower body, must not bend down into it, and sessions are short and always supervised — the gas is a circulatory remedy, not something to breathe.
What does the evidence say?
Carbon dioxide balneotherapy is better documented than some spa remedies, but the picture is still incomplete. Review articles confirm consistent, measurable physiological effects — notably skin vasodilation and improved peripheral blood flow — and several trials in peripheral arterial disease found that a course of CO₂ treatment improved pain-free and total walking distance in people with intermittent claudication, with benefits lasting some months. The limitation is that most studies are relatively small and of mixed methodological quality, so the findings are best described as promising rather than definitive. Sensibly used, mofette and carbonated-bath therapy is a supervised, complementary measure within cardiological care — never a replacement for prescribed medication or specialist treatment.
Sources
- Pagourelias ED et al. Carbon dioxide balneotherapy and cardiovascular disease. International Journal of Biometeorology (Springer). link.springer.com
- Toriyama T et al. Clinical and microcirculatory effects of transcutaneous CO₂ therapy in intermittent claudication (randomised double-blind trial). PubMed. pubmed.ncbi.nlm.nih.gov
- The Effect of Dry Carbon Dioxide Bathing on Peripheral Blood Circulation … among Patients with Risk Factors of PAD. Int. J. Environ. Res. Public Health. doi.org/10.3390/ijerph18041490
Recommended treatments
Covasna, Băile Tușnad and Balvanyos are well-known mofette resorts in the Eastern Carpathians.
| Resort | Main remedy | Recommended cure length | Season |
|---|---|---|---|
| Covasna | Natural mofettes & carbonated mineral water | 2–3 weeks | Year-round |
| Băile Tușnad | Mofettes & CO₂-rich springs, forest climate | 2–3 weeks | Year-round |
| Balvanyos | Natural mofettes, mineral springs | 2 weeks | Year-round |
| Vatra Dornei | Carbonated mineral-water baths, mountain air (800 m) | 2–3 weeks | Year-round |
| Buziaș | Carbonated (carbogaseous) mineral-water baths | 2–3 weeks | Year-round |
| Sângeorz-Băi | Mofette & mineral springs | 2 weeks | Year-round |
Good to know before you go
Typical cure duration
A single mofette session is short and strictly timed — usually about 10–20 minutes — because the carbon dioxide must not be inhaled. A full cure typically consists of daily sessions over about two to three weeks under supervision, often combined with carbonated baths, walks in the clean mountain air and a calm daily rhythm.
Contraindications
Mofettes are generally not advisable with unstable or severe heart disease, recent heart attack or stroke, decompensated heart failure, severe uncontrolled high or very low blood pressure, serious lung disease, during pregnancy, or for small children who would stand within the dense gas layer. Because the CO₂ pools near the ground, height, posture and supervision genuinely matter. A doctor must confirm suitability before treatment.
What to bring
- Comfortable clothing for the dry mofette and swimwear for carbonated baths
- Flat, non-slip footwear
- Your usual heart and blood-pressure medication
- A current list of your medications and relevant cardiology records for the spa doctor
FAQ
What are mofettes?
Mofettes are natural CO₂ dry baths: volcanic carbon dioxide escaping from the ground collects in special basins. Through the skin, the CO₂ stimulates peripheral circulation and is traditionally used for heart and circulatory complaints.
Are mofettes suitable for me?
For cardiovascular conditions, a treatment should always be assessed by a doctor beforehand. Stays take place under supervision, since the CO₂ collects at floor level and the time spent is limited.
How is the carbon dioxide thought to work through the skin?
Carbon dioxide is small and fat-soluble, so it is absorbed through the skin without water. It widens the small blood vessels near the surface, increasing skin blood flow and giving a feeling of warmth, and it can gently lower heart rate and blood pressure. In water-based carbonated (carbogaseous) baths the same effect eases the heart's workload. The gas contains roughly 95–98 percent carbon dioxide at natural Romanian mofettes.
What does the evidence say about carbon dioxide balneotherapy?
Reviews of carbon dioxide balneotherapy report measurable effects on the circulation, such as skin vasodilation, and some trials in peripheral arterial disease found improved pain-free walking distance after a course of CO₂ treatment. Overall the studies are relatively small and of mixed quality, so results are promising rather than definitive. Mofette therapy should be used as a supervised, complementary measure within cardiological care, not as a replacement for it.
How long does a mofette or CO₂ cure last?
A single mofette session is short and strictly timed, usually around 10 to 20 minutes, because the carbon dioxide collects at floor level and must not be inhaled. A full cure typically consists of daily sessions over about two to three weeks under supervision.
When are mofettes not advisable?
Mofettes are generally not advisable with unstable or severe heart disease, recent heart attack or stroke, decompensated heart failure, severe uncontrolled high or very low blood pressure, serious lung disease, during pregnancy, or for small children who would stand within the dense gas layer. Because the CO₂ pools near the ground, height and correct posture matter and stays are always supervised. A doctor must confirm suitability.
What should I bring for a heart and circulation cure?
Comfortable clothing for the dry mofette and swimwear for carbonated baths, flat non-slip footwear, your usual heart and blood-pressure medication, and a current list of your medications with relevant cardiology records for the spa doctor.
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