In this article
HOCATT is a branded ozone sauna: a seated steam and far infrared cabinet with the head outside, into which ozone and carbon dioxide are added while pulsed electromagnetic fields (PEMF) and microcurrent run, in a session the manufacturer describes as 30 minutes. Its name expands to "Hyperthermic Ozone and Carbonic Acid Transdermal Technology" in the original 2019 clinical case report, and the three published HOCATT studies are small reproductive-health reports with company involvement.[3]
- HOCATT is a combination ozone sauna chamber: the manufacturer lists steam, far infrared, ozone, carbon dioxide, PEMF, microcurrents and concentrated oxygen breathing among its components.[1]
- The user sits inside with the head outside the cabinet, according to the manufacturer's home-system page, and the manufacturer describes a 30-minute session.[1][2]
- Three original HOCATT reports have been published, all on reproductive health: Merhi et al. (2019, three women), Dias et al. (2023, 44 IVF patients) and Merhi et al. (2023, an endometriosis pilot with eight and ten women).[3][4][5]
- None of those studies had a randomized control group, and the full-text reports disclose HOCATT company involvement and a paid consultancy.[3][4]
- FDA registration is not FDA approval under 21 CFR 807.39, and the manufacturer states its products have not been assessed or approved by FDA.[2][7]
- FDA's ozone rule, 21 CFR 801.415, describes ozone as a toxic gas with no known useful medical application in specific, adjunctive or preventive therapy.[6]
Sources checked October 27, 2026. This is a device and research explainer, not a treatment recommendation or medical review.
What happens inside a HOCATT machine?
The manufacturer's current description lists steam, far infrared, ozone, carbon dioxide, pulsed electromagnetic fields (PEMF), microcurrents, concentrated oxygen breathing and other components.[1]
Its home-system page describes a seated chamber with the head outside.[2]
The manufacturer describes a 30-minute session, but that product description is not a recommended frequency or a personalized treatment plan.[1]
In practice, a HOCATT ozone sauna session means sitting in a heated, humid cabinet with the head outside while the device adds gases and runs its electrical components. The manufacturer also lists breathing concentrated oxygen during the session, which is separate from the ozone that goes into the cabinet.[1]
How does ozone reach the body in a HOCATT sauna?
HOCATT delivers ozone transdermally, which means the gas is released into the closed cabinet around the skin rather than injected or infused. The steam and far infrared heat warm the skin first, and the original case report describes the approach as hyperthermic ozone and carbonic acid transdermal technology.[3]
The head-outside design matters because ozone is a lung irritant. FDA's regulation on ozone-generating devices states that inhaled ozone can irritate the lungs enough to cause pulmonary edema, and that onset can be delayed by hours.[6] The US Environmental Protection Agency lists coughing, a sore throat, airway inflammation and worsened asthma among the effects of breathing ozone (EPA, health effects of ozone pollution).
Transdermal ozone is one of several routes used in ozone therapy. Others include major autohemotherapy, multi-pass ozone such as 10 pass, EBOO (extracorporeal blood oxygenation and ozonation), rectal insufflation and ozone injections into joints. Evidence from one route does not carry over to an ozone steam sauna.
How does HOCATT compare with other ozone saunas and therapies?
A HOCATT is one brand of ozone sauna. Generic ozone steam cabinets, sometimes called ozone steam saunas, combine steam heat and ozone in a similar seated, head-out cabinet without the full list of added components. Our overview of the ozone sauna covers that wider category.
| Option | How it is delivered | What the manufacturer or source states |
|---|---|---|
| HOCATT chamber | Seated cabinet, head outside, steam and far infrared heat with ozone and carbon dioxide added | The manufacturer also lists PEMF, microcurrents and concentrated oxygen breathing, and describes a 30-minute session.[1][2] |
| Generic ozone steam sauna | Seated cabinet, head outside, steam heat with ozone added | Configurations vary by maker. No HOCATT study described in the studies section tested a generic cabinet. |
| Far infrared sauna | Heat only, usually without ozone | Shares the heat component listed for HOCATT but adds no gas exposure.[1] |
| Systemic ozone therapy, such as 10 pass or EBOO | Blood is drawn, exposed to ozone and returned | A different, invasive route. See our comparison of EBOO and 10 pass ozone. |
Do all HOCATT pages describe the same configuration?
The two manufacturer pages checked do not present identical component lists. The How It Works page includes essential-oil infusions and ultraviolet irradiation; the home page instead lists ultrasonic cavitation and separates microcurrents from frequency-specific microcurrents.[1][2]
That discrepancy leaves the offered configuration unresolved. Ask the provider for the model, serial-label details, included accessories and current operating manual rather than assuming every HOCATT has every advertised component.
Treat the manufacturer's descriptions as product claims, not independently measured clinical outcomes. The questions below separate the equipment being offered from the research being cited.
What have published HOCATT studies measured?
These three original reports studied different reproductive-health questions. Their populations and endpoints should remain separate; they are not three trials of general detoxification or everyday wellness.[3][4][5]
| Original report | Participants and observation | Reported measurements and limits |
|---|---|---|
| Merhi et al., 2019 case series | Three women with persistently thin endometrial lining during frozen embryo transfer care; three weeks of combined exposure alongside hormonal treatment. | Lining measurements reached 7, 6.7 and 6.7 mm. Two pregnancies were reported: one ongoing at manuscript preparation and one ending in miscarriage. There was no randomized or untreated comparison, and no two-live-birth result.[3] |
| Dias et al., 2023 IVF and laboratory report | 50 recruited: 44 with diminished ovarian reserve in sequential IVF cycles before and after three weeks of exposure; six other participants supplied cells for laboratory work. | The authors reported higher embryo counts and lining thickness in the later cycle, but no significant change in retrieved oocyte counts or peak estradiol. Pregnancy and implantation rates were not assessed. This was not a randomized parallel-group trial.[4] |
| Merhi et al., 2023 endometriosis pilot, abstract reviewed | Eight women in the pain study; ten women in the biomarker study, both over three weeks. Group overlap was not specified. | The abstract reports lower pain scores, lower CRP and IL-1 beta, and higher IL-8. It does not describe a control arm or provide absolute changes. Full text was inaccessible for this review.[5] |
The 2019 case series appeared in the journal Medicine, the IVF report in Medical Gas Research and the endometriosis pilot in the American Journal of Reproductive Immunology.[3][4][5] All three came from fertility and reproductive medicine settings, where reproductive endocrinologists manage the underlying care.
Has HOCATT been studied for detox, Lyme disease or mold illness?
No published HOCATT study among the three reviewed here measured detoxification, Lyme disease, toxic mold exposure, chronic fatigue syndrome, weight loss or skin health. Ozone saunas are marketed for those uses, and those claims rest on manufacturer and clinic descriptions rather than on HOCATT trial results.[3][4][5]
What remains unresolved in those reports?
The IVF paper states a 44-person clinical sample, but its supplementary degrees of freedom do not reconcile with that denominator under the stated paired analysis. Two laboratory table directions also conflict with the prose. These unresolved details prevent a clean numerical interpretation of those results.[4]
Both full-text reports disclose HOCATT company involvement and a paid consultancy. Those disclosures belong beside the reported findings, not only in a bibliography.[3][4]
The endometriosis abstract lists HOCATT affiliations, but its full funding, conflict statement and detailed methods were not available in the retrieved material.[5]
These human studies concern combined ozone and PEMF exposures; the reproductive protocols included intravaginal administration as well as transdermal exposure. They should not be treated as descriptions of every ordinary sauna visit.[3][4][5]
Regenerated.com does not infer an individual benefit, safety conclusion, fertility recommendation or operating protocol from those reports.
What does FDA registration tell you about HOCATT?
Registration alone does not establish FDA approval. Section 807.39 of Title 21 says that registration or a registration number does not denote approval of an establishment or its products.[7]
The manufacturer's home page also states that its products have not been assessed or approved by FDA and are not designed to diagnose or treat disease. That is the manufacturer's disclaimer, not an independent model-specific database determination.[2]
Section 801.415 addresses ozone-generating devices, including labeling and specified adulteration or misbranding conditions. The eCFR text checked was current through October 23, 2026. This page does not turn its concentration provisions into sauna settings or decide a particular device's legal status.[6]
The same section opens by stating that ozone is a toxic gas with no known useful medical application in specific, adjunctive or preventive therapy.[6] Our explainer on whether ozone therapy is FDA approved covers how that rule applies across ozone routes.
If a provider claims FDA clearance or authorization, ask for the actual decision record, manufacturer, model and intended use. A registration certificate is not a substitute for that documentation.[7]
Is a HOCATT ozone sauna safe?
No published study has established the safety of a HOCATT ozone sauna for general use. The three reports enrolled small numbers of fertility and endometriosis patients for three weeks, and none was designed as a safety trial.[3][4][5]
The known risks come from the components. Heat and steam raise body temperature and can cause dehydration, dizziness or fainting. Ozone that escapes the cabinet and is breathed in irritates the airways and lungs, according to FDA's ozone rule and the EPA.[6]
Before a session, ask the clinician how they screen for heart disease, low or uncontrolled blood pressure, pregnancy, asthma and other lung disease, heat-sensitive conditions such as multiple sclerosis, and implanted electronic devices, given the PEMF and microcurrent components. For a wider view of reactions reported across ozone routes, see our page on ozone therapy side effects.
Who offers HOCATT ozone sauna sessions?
HOCATT sessions are mostly offered by integrative and functional medicine clinics, naturopathic practices, chiropractic offices and wellness centers that already provide ozone therapy, often alongside hyperbaric oxygen therapy (HBOT), red light therapy and IV therapy. The published studies came from fertility settings, but day-to-day providers are usually cash-pay wellness clinics.[3][4]
The clinician who screens you and the staff member who runs the machine are often different people. Ask who holds the medical license on site, whether a physician, nurse practitioner or naturopathic doctor reviews your history, and who is present during the session.
What should you ask before arranging a clinic visit?
Ask which components the proposed appointment includes, who operates the equipment, who conducts the clinical assessment and which qualifications can be checked. Request the written screening process and device documentation rather than a benefits list.
Ask whether the cited paper used the same equipment configuration, administration route and patient population as the service being offered. Request the original report, not just a testimonial or a study headline.
For the quote, request the consultation charge, session charge, any package commitment and cancellation terms separately. This page makes no pricing commitment and recommends no session schedule.
Is a HOCATT session covered by insurance?
HOCATT sessions are generally cash pay. The device is not FDA approved for treating any disease, according to the manufacturer's own statement, so check coverage with your health plan directly rather than assuming it.[2] Ask for a written, itemized quote before booking a package, and ask whether an HSA or FSA receipt can be issued.
Where can you compare Ozone Therapy clinic records?
Regenerated.com's September 2026 export contains 846 clinic records listing Ozone Therapy within a sample of 9,042 US clinics, across 48 states plus the District of Columbia. This is directory category coverage, not a count of HOCATT machines, confirmed HOCATT operators or fertility specialists.
Browse the Ozone Therapy clinic directory, or compare the recorded category in Alaska, California and Connecticut.
Two records that list Ozone Therapy are Alliance Regenerative Medical Centers of Clermont in Florida and Next Health Lincoln Park in Illinois. These are category-navigation examples, not endorsements or confirmation that either location offers HOCATT. Confirm the exact service directly with the provider.
Listing order in the directory is not paid ranking. Featured slots are labeled and capped, Verified means the clinic completed credential checks rather than paid for placement, and Regenerated.com is free for patients. Inclusion is not an endorsement; our guide to Featured, Verified and organic listings explains each label.
When you search the national list of ozone therapy clinics, filter by your state, then contact each clinic to ask whether it operates a HOCATT or a different ozone sauna. Our ozone sauna therapy overview can help you compare what each one describes.
Frequently asked questions
What does HOCATT stand for?
HOCATT stands for "Hyperthermic Ozone and Carbonic Acid Transdermal Technology," the expansion given in the 2019 case report by Merhi and colleagues.[3] The name describes the method: heat from steam and far infrared, ozone and carbon dioxide gas, and delivery through the skin inside a seated cabinet. HOCATT is a brand name for one manufacturer's ozone sauna chamber, not a generic term for every ozone steam cabinet.
Does your head go inside a HOCATT chamber?
No, your head stays outside. The manufacturer's home-system description says the user is seated with the head outside the chamber.[2] That layout keeps the face away from the ozone released inside the cabinet, which matters because FDA describes inhaled ozone as a lung irritant. The layout describes the design only and is not a safety determination, so ask how the clinic controls leakage around the neck opening.
Is a HOCATT registration number proof of FDA approval?
No. Under 21 CFR 807.39, registration or a registration number does not denote approval of an establishment or its products.[7] The manufacturer also states that its products have not been assessed or approved by FDA. If a clinic claims FDA clearance or authorization, ask for the actual decision record and check it against the exact device, model and intended use.
Does an Ozone Therapy listing confirm HOCATT availability?
No. Our directory records the broader Ozone Therapy category, which can include several ozone routes, not only saunas. A listing does not establish the installed device brand, its configuration or current appointment availability. Before you book, ask the clinic to confirm that it operates a HOCATT, which model it has and which components your session will include.
How long is a HOCATT ozone sauna session?
The manufacturer describes a HOCATT session as 30 minutes.[1] That figure is a product description, not a recommended frequency or a personalized plan. In the published fertility studies, participants used combined exposures over three weeks, but those protocols also included intravaginal ozone and do not translate to an ordinary wellness visit. Ask the clinic how it decides session length and spacing for you.
Is a HOCATT ozone sauna safe?
Safety has not been established by published research. The three HOCATT studies were small, short and not designed to measure safety.[3][4][5] Known risks come from the parts: heat can cause dehydration and dizziness, and breathed ozone irritates the lungs, according to FDA's rule on ozone devices.[6] People with heart or lung disease, pregnancy or implanted devices should ask a clinician first.
Sources
- HOCATT: How HOCATT Works, checked October 27, 2026. Checked October 27, 2026.
- HOCATT: Home system, checked October 27, 2026. Checked October 27, 2026.
- Merhi et al., Medicine (2019): Three HOCATT case reports. Checked October 27, 2026.
- Dias et al., Medical Gas Research (2023): IVF and granulosa-cell study. Checked October 27, 2026.
- Merhi et al., American Journal of Reproductive Immunology (2023): Endometriosis pilot, abstract only. Checked October 27, 2026.
- eCFR: 21 CFR 801.415, current through October 23, 2026. Checked October 27, 2026.
- eCFR: 21 CFR 807.39, current through October 23, 2026. Checked October 27, 2026.