Who Should Not Get EBO2 (EBOO)? Contraindications and Precautions

EBO2 (also called EBOO) is not appropriate for everyone, and every clinic that screens patients carefully maintains some version of a list of who should not receive it. See the pillar guide if you need the mechanism and evidence overview first. Because ozone therapy is not FDA-approved for any condition [7], there is no single federally reviewed contraindication list; what exists instead is a body of practitioner guidelines, case reports, and individual clinic policies that overlap on most major points. This guide walks through what is commonly listed as an absolute contraindication versus a relative precaution, the reasoning behind each, and what a thorough intake screening should look like. None of this is a substitute for a conversation with a clinician who knows your specific health history; it is a way to recognize what a responsible screening process should cover before you have that conversation.

Contraindications clinics commonly list

Sources do not all agree on how firm each item below is. One Kansas clinic’s own published screening list, for instance, separates a short “absolute contraindications” tier from a longer “case-by-case” tier, and only G6PD deficiency (alongside favism, the related hemolytic condition) sits in its absolute category; that same clinic treats uncontrolled hyperthyroidism, thrombocytopenia, and a recent heart attack as things it weighs case by case rather than automatic exclusions [5]. Other practitioner sources discuss several of the same conditions together without drawing that same absolute-versus-case-by-case line [1]. Where a clinic places a given condition is worth asking about directly rather than assuming from a general list like this one.

G6PD deficiency

Glucose-6-phosphate dehydrogenase, or G6PD, deficiency is the contraindication that shows up most consistently across both the peer-reviewed literature and clinic policies, and it is the one item the Kansas clinic above lists as absolute rather than case-by-case [5]. People with a significant G6PD deficiency have red blood cells that are less able to neutralize oxidative stress, and ozone is, by design, an oxidant. A 1977 toxicology paper modeled how G6PD-deficient red cells could undergo hemolysis, the breakdown of red blood cells, on exposure to ozone at levels far lower than what would affect someone with normal enzyme activity [2]. That paper models inhaled, ambient-level ozone of the kind found in polluted air, not the brief, controlled contact between ozone and blood that EBO2 uses, so it is a theoretical model rather than a direct study of this or any other ozone therapy. It is nonetheless specific enough, and consistent enough with how G6PD deficiency behaves with other oxidative triggers, that it anchors why a G6PD blood test appears in intake screening at clinic after clinic [5].

Pregnancy

Pregnancy, particularly in its early stages, is commonly listed as a contraindication, largely out of caution against any unproven mutagenic or developmental risk rather than a documented harm in pregnant patients specifically [1]. Clinics that screen well ask directly rather than assuming.

Uncontrolled hyperthyroidism

Practitioner sources list uncontrolled hyperthyroidism, including Graves disease, as a reason for caution [1]. The Kansas clinic above places it in its case-by-case tier rather than its absolute one, meaning it is weighed against the rest of a patient’s history rather than an automatic bar [5]. An overactive thyroid already increases metabolic demand and cardiovascular strain, and clinics treat that as a reason for added caution around a procedure that introduces its own oxidative and circulatory load, even where it does not rule someone out on its own.

Active bleeding or severe thrombocytopenia

A bleeding disorder, severe thrombocytopenia (a low platelet count), or an active bleeding episode raises the stakes of any procedure built around two IV placements and an external blood circuit. The same Kansas clinic lists severe thrombocytopenia, coagulation problems, and bleeding disorders or hemorrhagic stroke in its case-by-case tier rather than its absolute one [5], though a clinic evaluating an active bleeding episode in front of it may reasonably decline to treat that day regardless of which tier its policy assigns the underlying condition to.

Recent heart attack or stroke

A recent myocardial infarction is commonly listed as a reason for caution [1], and the Kansas clinic above places it in the same case-by-case tier as hyperthyroidism and thrombocytopenia rather than its absolute list [5]. The reasoning is general caution around introducing a new circulatory and oxidative stressor soon after a cardiovascular event, alongside the practical reality that someone recovering from a heart attack or stroke is a poor candidate for any elective procedure with an uncertain benefit.

Ozone allergy

True allergy to ozone itself is rarely well documented and is sometimes conflated with the airway hypersensitivity some people with asthma experience around polluted, ozone-containing air, which is a different phenomenon from a reaction to a controlled medical exposure [1]. Even so, a clinic that hears about a prior adverse reaction to any form of ozone therapy should treat that history as a reason to proceed cautiously or not at all, whatever the underlying mechanism.

Relative precautions

A second tier of conditions is commonly treated as something to evaluate and manage rather than an automatic bar to treatment. These include being on anticoagulant medication, having poor or difficult venous access, low blood pressure, severe anemia, an active infection with a fever, and uncontrolled diabetes [5]. A clinic that takes these seriously will ask about them directly and may still decline to treat you, ask you to stabilize the underlying condition first, or adjust how it approaches the procedure. None of these automatically rules out EBO2 the way the conditions above commonly do, but each is a reason for a more careful conversation before booking rather than after arriving.

Poor venous access deserves a specific mention because EBO2 depends on reliable access in both arms for the length of the session. A single successful draw is not enough; both lines have to hold for the full hour. Someone whose veins are difficult to access, from prior chemotherapy, repeated blood draws, or anatomy, may need a more experienced clinician placing the lines or may not be a good candidate for this particular procedure even if no other precaution applies. Severe anemia is worth flagging separately from the general caution around blood disorders: removing and circulating blood outside the body, even briefly and even when returned in full, is a reasonable thing to approach carefully in someone whose blood count is already low, which is part of why a complete blood count commonly appears on intake labs rather than being assumed normal [5].

Medication interactions clinics ask about

A few specific medications come up repeatedly in clinic screening beyond the general caution around anticoagulants. ACE inhibitors, a common class of blood pressure medication, have been linked to marked drops in blood pressure when ozonated blood is reinfused too quickly, an effect attributed to activation of a blood pressure-related enzyme cascade that resolves as the medication clears the reinfused blood [1]. Patients on iron infusions or with hemochromatosis, a condition involving excess iron storage, and patients with a known allergy to heparin, the anticoagulant commonly used in the circuit itself, also appear on clinic screening lists [5]. None of this means these medications or conditions make EBO2 impossible, but they are exactly the kind of detail an intake conversation is supposed to surface before your first session rather than during it. Bring a current medication and supplement list to your intake appointment, including anything you take occasionally rather than daily, since a clinician cannot ask about an interaction they do not know to look for.

Why screening labs matter

The contraindications above are the reason several clinics run baseline labs before a first EBO2 session rather than relying on a conversation alone. One clinic’s stated intake panel includes a comprehensive metabolic profile, a complete blood count, a G6PD enzyme test, fasting insulin, C-reactive protein, and D-dimer, a marker used to help evaluate clotting risk [5]. Labs catch what a conversation might miss: someone can be entirely unaware of a G6PD deficiency until it is tested for, since it produces no symptoms on its own until triggered by an oxidative exposure. A broader consensus document on ozone therapy maintained by an international scientific committee devotes a specific section to contraindications alongside its guidance on routes of application, reflecting an attempt at standardizing this kind of screening across practitioners rather than leaving it to each clinic to define from scratch [4], and a 2025 paper from an Italian ozone therapy society argues in similar terms for standardized protocols across the field to protect patient safety [3].

Questions to expect at intake, and red flags if a clinic asks none

A careful intake should ask about your full medical history, current medications and supplements, any bleeding disorders, thyroid disease, pregnancy status where relevant, recent cardiovascular events, and prior reactions to ozone or similar therapies, and should either run or ask about recent bloodwork covering the conditions above. One clinic that lists eligibility criteria directly states that patients are not eligible for EBO2 if they have cancer, are pregnant or breastfeeding, take high doses of vitamin K, or have a genetic clotting disorder, and describes screening every client for contraindications before treatment [6]. If a clinic instead moves straight from a sales conversation to scheduling without asking about any of this, that is a meaningful red flag, not a sign of an especially simple or low-risk procedure. A short intake is not the same as no intake, and it is reasonable to ask directly what a clinic screens for if its process is not already clear from its own materials, available alongside pricing in the clinic directory.

It is also reasonable to ask what happens if screening turns something up. A clinic with a real process should be able to describe what it does when a patient’s labs or history raise one of the concerns above: decline treatment outright, refer the patient back to their own physician first, or adjust the procedure in a specific, describable way. A vague answer, such as a general assurance that the clinic “screens everyone” without detail on what that means in practice, tells you less than a clinic willing to walk through an example.

Bottom line

Most sources on ozone-based therapies, from individual clinics to international practitioner groups, converge on a similar list of reasons to avoid or delay EBO2: G6PD deficiency, pregnancy, uncontrolled hyperthyroidism, active bleeding problems, a recent heart attack or stroke, and a scattering of medication interactions and relative precautions worth a closer look [1][5]. None of this comes from an FDA-reviewed standard, since ozone therapy is not FDA-approved to treat any condition [7], which makes a clinic’s own screening process the main safeguard in practice. Treat a thorough intake, not a quick sales call, as the sign of a clinic taking that responsibility seriously, and read the side effects and safety guide and the what to expect guide alongside this one before you decide.