EBO2 (EBOO) Side Effects and Safety: What Studies, Case Reports, and Regulators Record

EBO2 (also called EBOO) has almost no safety record of its own. Our library classes six papers as studies of EBOO as given to people; four come from the Siena group that developed the method. None attributes an adverse event to the procedure, though one case report notes a fall in hemoglobin and that the patient felt worse after her second series, and none was built to detect uncommon events. We found no published case report of a serious adverse event during EBO2 itself. The serious harms documented with ozone, among them strokes, blindness, heart attacks, infections, and deaths, come from other procedures that put ozone into blood or tissue. This guide sets out what each kind of source records, so a reader can see where the evidence is thin and what to ask about it.

Ozone therapy is not FDA-approved for any condition, and federal regulation calls ozone “a toxic gas with no known useful medical application in specific, adjunctive, or preventive therapy” [18]. Our pillar guide explains the procedure; the case-by-case list of reported harms is in our ozone therapy adverse events guide.

How much EBOO-specific safety data exists

Every paper our library classes as a study of EBOO as given to people, and what it says about adverse events:

The ozone dialysis paper’s 400 sessions are the practitioners’ own statement, not a counted safety record [7]. One related circuit adds little: a six-patient pilot study of 10-pass ozone describes no adverse events [8]. The developers’ 2007 bench test of their gas exchanger used a saline solution and no patients, so it holds no safety data about people [5]. The prostacyclin comparison group’s side effects are not given in the trial’s abstract, and the trial’s full text is behind a paywall [3]. The table under “From our data” below shows the procedure each EBOO paper reports.

Small studies can miss uncommon events, and none of these papers counted events in a way that would give a rate. A 2026 scoping review of autohemotherapy safety concluded that the overall rate of serious adverse events cannot be reliably estimated, for want of registries and of reliable counts of treatments given [21].

What clinics say about side effects

Clinic pages describe mild, short-lived effects. A Pennsylvania clinic says side effects are generally minimal but can include slight fatigue or localized bruising [9]. A California clinic mentions temporary fatigue or dizziness that typically resolves quickly [10]. An Arizona clinic lists brief fatigue, what it calls a detox response in the 24 hours after treatment, and temporary vein discomfort at the IV site as the most common effects [11]. The longest list comes from a Beverly Hills practice whose EBOO page offers a consultation about the procedure without saying it performs it: infection, clotting, bleeding in people taking blood thinners, damage to red blood cells, low blood pressure, fainting, and vein injury, as reported and potential risks [12].

These are statements by medical businesses, three of which sell the procedure. None of the pages gives a number of patients treated or events seen, so they describe what a clinic chooses to say, not what its patients experienced.

Risks specific to an extracorporeal circuit

EBO2 draws blood from a vein in one arm, runs it through an extracorporeal circuit with a filter and gas exchanger, and returns it through a vein in the other arm. The NIH kidney institute’s page on hemodialysis, another procedure that circulates blood outside the body, lists an access that becomes infected or blocked by a blood clot, blood loss if a needle comes out, and a sudden drop in blood pressure during treatment, which it attributes to sudden changes in the body’s water and chemical balance [13]. MedlinePlus, writing for people with a dialysis access, lists bleeding from the access, signs of infection, a fever of 100.3°F (38.0°C) or higher, and a hand that turns cold, numb, or weak among the reasons to call a provider [14]. A temporary IV is not a surgical dialysis access, but the access problems are of the same kind.

The circuit also needs an anticoagulant to keep blood from clotting in the tubing. The EBOO review describes the blood as heparinized [4], and the label of a heparin product approved by FDA warns that bleeding, including fatal bleeding, has occurred with heparin, and lists a history of heparin-induced thrombocytopenia, a serious immune reaction to heparin, among the reasons not to use it [15]. What that means for people who take blood thinners is covered in our blood thinners and medicines guide, and bleeding disorders in our contraindications guide.

The filter matters too. The Siena group that developed EBOO wrote in 1999 that dialysis-type semipermeable membranes were unsuitable for ozone because they are hydrophilic and vulnerable to it, and used ozone-resistant hollow fibers instead [41]. In 2010 the same group tested four dialysis filters, found gas exchange ranging from 0 to 70%, saw ozone alter the fibers, and warned that because their materials may not be ozone-resistant, they may release compounds harmful to patients [42]. FDA’s 2025 warning letter describes a maker selling EBOO kits built around hemodialyzer filters [34], and the 2023 ozone dialysis paper used a cellulose triacetate dialysis chamber [7]. Our devices guide and our comparison of EBOO and dialysis cover the equipment.

Two effects come from the way blood is returned in related procedures. Bocci, the Siena physiologist whose group reported about 800 EBOO sessions, describes tingling of the lips and tongue near the end of reinfusion in autohemotherapy, which he attributes to excess citrate anticoagulant given too quickly, and a sudden, marked fall in blood pressure when ozonated blood was reinfused quickly into patients taking ACE inhibitors, an observation he calls unpublished and says he confirmed in two patients [16].

Risks specific to ozone

Breathing it. Federal regulation says inhaled ozone can irritate the lungs enough to cause pulmonary edema, usually some hours after exposure [18], and a 1989 review found that ozone at peak outdoor levels causes measurable, temporary changes in lung function, symptoms, and airway inflammation in healthy people [19]. FDA has received reports of asthma attacks, headaches, and breathlessness from people using ozone devices sold to clean CPAP machines [20].

G6PD deficiency. A 1977 paper modeled what might happen to people with glucose-6-phosphate dehydrogenase deficiency exposed to ozone at levels reached in some cities, and predicted they may experience acute hemolysis, the breakdown of red blood cells [17]. It is a one-sentence abstract about inhaled air, not a study of any ozone therapy. Bocci lists a significant G6PD deficit among the situations that preclude or limit ozone therapy and says patients should be checked for it [16]. See G6PD deficiency and our contraindications guide.

Dose. The Siena review reports that a session of EBOO raised a blood marker of oxidation four- to five-fold without appreciable breakdown of red blood cells [4]. The 2026 scoping review links hemolysis and kidney failure to ozone concentrations above 60 μg/mL in autohemotherapy [21]. EBOO papers rarely state the dose a given patient received.

Complications reported in the wider ozone-therapy literature

The sinus-arrest case involved a woman with high blood pressure, diabetes, and chronic kidney disease whose potassium rose to 6.8 mmol/L after nine days of autohemotherapy; her authors hypothesize a link to the therapy, and her rhythm and potassium returned to normal with treatment [22]. In two randomized trials of autohemotherapy, one recorded no complications in either group [23] and one recorded temporary facial redness in 3% of patients [24].

Two patterns run through the serious reports. The neurological and heart events began during the procedure or within minutes, and most authors attribute them to gas entering the bloodstream; several patients had a patent foramen ovale, an opening between the heart’s upper chambers that the authors describe as the route bubbles took to the brain [26][28][29]. The infections followed both blood procedures and injections, and authors tie them to lapses in sterile technique [39]. The full list, by route and with each paper’s own causation wording, is in our adverse events guide.

What regulators and courts have recorded

These records use their own words, quoted here.

• New York, 2023. Upholding a medical examiner’s finding that a podiatrist’s patient died by homicide due to extreme medical negligence, the Appellate Division wrote: “The medical examiner also observed gas emboli and concluded, based on their existence in both small and large blood vessels, that they were attributable to the injection of ozone.” The court cites evidence that he injected the patient intravenously with ozone gas and that cardiac arrest followed within 15 minutes [31].
• California, 2024. A physician admitted an accusation that, during intravenous ozone therapy in 2020, a patient’s IV made sounds “indicating a potential air leak”, after which she lost consciousness and was diagnosed with air embolism and stroke. The Medical Board of California’s order states: “During probation, Respondent is prohibited from performing intravenous ozone therapy treatment.” [32]
• New South Wales, 2025. The Health Care Complaints Commission barred an ozone clinic from providing health services for five years, finding that its practitioner’s treatment “was, according to expert opinion, the most likely reason that she contracted a serious infection which led to septic shock”. It also found that he obtained heparin “from an unknown source” and “is not authorised to be in possession of, or to administer” it, that he tried to sterilize single-use items for reuse, and that he used a “Champion Full Spectrum UV device” not approved in Australia [33].
• FDA, 2025. A warning letter to O3UV, LLC says its “Champion Full Spectrum” and “EBOO Full Spectrum UV” autohemotherapy devices lack premarket approval or clearance, and that the firm “had no complaint procedure in place to receive, review, and evaluate complaints”. It notes that the firm’s EBOO kits included hemodialyzer filters bought from another company without supplier controls [34].
• FDA, 2024. On ozone CPAP cleaners: “The FDA has received reports from people who use CPAPs that they experienced unexpected asthma attacks, headaches, and breathlessness after using devices claiming to use ozone gas to clean CPAP accessories such as hoses and masks.” [20]
• FDA, 2014. A Class 2 recall of an ozone generator gives the reason as: “William Domb is recalling the Enaly 1000 BT-12 Ozone Generator because it is not approved or cleared by the FDA for medical use.” The record concerns marketing status, not an injury [35].
• Italy, 2005. The Health Ministry relayed the national health council’s 2003 opinion that no controlled clinical studies support oxygen-ozone therapy and that the method can cause serious and potentially lethal side effects (our translation) [36].

The FTC’s 2020 warning letters to ozone clinics concerned marketing claims about COVID-19, not the physical safety of the procedure [37]. The regulatory tracker holds every record with its exact language.

Signs described in the sources

MedlinePlus lists bleeding from the access site, redness, swelling, soreness, pain, warmth, or pus around it, a fever of 100.3°F (38.0°C) or higher, an arm that swells with a cold hand on that side, and a hand that gets cold, numb, or weak as reasons for people with a vascular access to call their provider [14]. In the case reports of other ozone procedures, the serious events showed as chest pain, fainting, a seizure, sudden loss of vision, weakness on one side, confusion, or trouble speaking, usually within minutes [26][28][29][30].

Questions to ask a clinic, and checks to run

Our guide to choosing a clinic has a longer list; these come from the sources above.

• Who places the lines, who supervises, and is a physician on site for the whole session?
• What happens if something goes wrong? Bocci writes that anyone giving ozone therapy should know basic life support and keep a breathing bag, medical oxygen, a defibrillator, and emergency drugs at hand [16].
• Which anticoagulant does the circuit use, and how much? What does the clinic do for someone who takes a blood thinner?
• What ozone concentration and session length does the clinic use, and is the filter and gas exchanger new for each patient?
• Which device is used, and what is its FDA status? Our guide to whether EBO2 is FDA-approved explains the terms.
• What should I watch for afterwards, and how do I reach the clinic after hours?
• Has the clinic had any adverse events, and did it report them to FDA?

Checks a reader can run: search FDA’s MAUDE database for the device’s name and read the MedWatch steps in our adverse events guide; look for the clinic or its physicians in our regulatory tracker; compare what clinics publish in our clinic directory; and build a list of questions for your own doctor with our doctor questions tool. Problems can be reported to FDA through the MedWatch form [38].

What we could not verify

• The size of the risk with EBO2. No study was designed to measure it, and no registry or reporting system collects EBO2 outcomes.
• The EBOO trial’s full text, which might describe side effects in more detail than its abstract, including in the comparison group.
• The ACE inhibitor observation, which rests on an unpublished report and two patients described in a book chapter.
• Whether today’s EBO2 equipment matches the Siena prototype. FDA’s 2025 letter shows at least one maker selling EBOO kits built around hemodialyzer filters from another company [34]. No study we found measured what such filters release into a patient during a session, the concern the Siena group raised in 2010 [42].
• Dose. Few EBOO papers report the ozone concentration given, so no dose and harm pattern can be drawn.

How this guide was made

We used 43 sources: the six EBOO papers in our library, three Siena equipment papers, one related study, fourteen other papers and reviews and one book chapter read through NCBI and Europe PMC, eleven government and court records, an FDA-approved drug label, two patient-education pages, and four clinic pages we saved on September 28, 2026, labeled clinic-stated. The table under “From our data” is computed from our study cards when the site is built, and the regulators’ records shown there come from our regulatory dataset. Drafting used AI tools. A human editor has not yet checked this guide claim by claim against its sources, and no clinical reviewer has signed off yet.