EBO2 (EBOO) for Athletes: Anti-Doping Rules, the Studies, and the Claims

For an athlete who competes under an anti-doping code, the first question about EBO2 (also called EBOO) is usually eligibility rather than recovery: whether the procedure is permitted under the rules that athlete is tested against. This guide sets out the rule wording as anti-doping organizations publish it, the one documented sanction involving ozone therapy, what the published research has measured, and how many clinic pages in our directory market the procedure to athletes. It does not say whether the procedure is permitted for any athlete; only that athlete’s anti-doping organization can answer that.

The Harper announcement, and what it is not

In December 2025 Philadelphia Phillies player Bryce Harper posted that he had undergone EBOO, describing a procedure in which a third of his blood was drawn, passed through a filtration and ozonation device, and returned, and crediting it with better circulation, less inflammation, and more energy [11][12]. Sports coverage reported that the FDA has not approved ozone therapy for treating or preventing illness, and that nothing indicated he had broken a league rule [11][13].

A public account of how a treatment made someone feel is not a measurement. No blood test, power output, or blinded comparison attaches to it, and an offseason contains simultaneous changes to training, sleep, and nutrition that no anecdote can separate. Its real effect has been commercial: a well-known name attached to a procedure that, as the sections below show, has no study behind it in athletes and an unresolved eligibility question in front of it.

Why eligibility comes first

Anti-doping rules work on strict liability: the athlete is responsible for what enters their body and for the methods used on them, whether or not anyone intended an advantage and whether or not the clinic knew the rules. That makes the order of questions unusual here. For most elective treatments the questions are benefit, risk, and cost. For a competing athlete, a method that turns out to be prohibited can carry a sanction measured in years of eligibility (the standard period in the one ozone case below was two years [5]), so the eligibility question comes first.

Two features of EBO2 make this a live question rather than a formality. Blood leaves the body and is returned to it. And the volume of fluid going back into a vein is far larger than the threshold that anti-doping rules set for infusions. Both are addressed in the rule wording below, and neither depends on whether EBO2 does anything useful.

What the Prohibited List says, as anti-doping agencies word it

The World Anti-Doping Agency’s International Standard, the Prohibited List, is revised each year, and each new List takes effect on 1 January [3]. WADA’s website refused our automated requests for the 2026 and 2027 Lists, so we have not read either document; the wording below is as three anti-doping organizations publish it on their own pages [1][2][3]. None of those three pages names EBO2, EBOO, or ozone therapy.

The List’s M1 class, Manipulation of Blood and Blood Components, is prohibited at all times, in and out of competition [1]. Germany’s national anti-doping agency, NADA, summarises the class on its English-language page: “blood transfusions, dialysis (i.e. ‘blood washing’) and the administration of red blood cell products of any origin into the circulatory system are prohibited”, and “Any form of intravascular manipulation of the blood or blood components by physical or chemical means is also prohibited” [1].

The Athletics Integrity Unit, summarising WADA’s explanatory note for 2026, reports a clarification in the same class: “The withdrawal of blood or blood components is prohibited”, unless it is for analytical purposes, such as medical testing or doping control, or for donation at an accredited collection centre. In the unit’s words, this “closes a gap in earlier wording by recognising that manipulation begins at the point of withdrawal, not only reinfusion”, and “Platelet-Rich Plasma (PRP) procedures remain not prohibited” [2].

Under the M2 class, Chemical and Physical Manipulation, NADA lists intravenous infusions among its examples [1]. USADA states the infusion rule as a volume limit, 100 mL in a 12-hour period outside hospital, surgical, and diagnostic settings, in the wording quoted in the next section [4][6].

A widely shared sports write-up about EBO2 told readers that the Prohibited List “explicitly targets techniques in which blood leaves the body, undergoes manipulation, and returns—ozone-based and ultraviolet-light treatments included”, and linked to WADA’s 2019 list [13]. We could not read that List, or the current ones, to check the claim. The agency pages we read describe the blood rules in general terms and do not name ozone or ultraviolet treatments; only USADA’s separate guidance, quoted below, names ozone autohemotherapy. That is one reason the answer for any athlete rests with an anti-doping organization rather than with a sports column.

What USADA tells athletes about ozone therapy and clinic IVs

The United States Anti-Doping Agency publishes guidance for athletes on treatments sold by wellness and anti-aging clinics, and it addresses ozone therapy by name. Its page states: “With one type of ozone therapy, blood is removed from a vein, infused with ozone, and then reinjected back into the body. This method of ozone therapy, called autohemotherapy, is prohibited at all times. While ozone itself is not prohibited as a substance, all treatments that remove and reintroduce blood into the circulatory system are prohibited.” The same page states that ozone therapy given by rectal insufflation is permitted [4].

The page addresses the infusion volume separately: “All intravenous injections of more than 100 mL in a 12-hour period are prohibited at all times, regardless of what is in the IV bag”, with the exception of an IV “legitimately received in the course of hospital treatment, surgical procedures, or clinical diagnostic investigations”. It then adds a sentence about clinics: “For the purpose of anti-doping rules, wellness or anti-aging clinics are not considered a hospital setting” [4]. USADA’s longer note on infusions lists the settings where an over-threshold IV is still prohibited, among them “any type of health clinic, health center, wellness clinic, or any kind of IV clinic, dialysis center, or treatment room outside of a hospital facility that is not part of a surgery or diagnostic test” [6].

How this maps onto EBO2 is a question for an athlete’s anti-doping organization, not for us. What we can say is that the description clinics give of EBO2, blood drawn from one arm, passed through a filter and an ozone circuit, and returned through the other (see what EBO2 is), is a description of blood being removed from and reintroduced into the circulatory system, and of a return volume far above 100 mL. Nothing in USADA’s guidance names EBO2, and we make no ruling about any individual’s eligibility.

The one documented sanction

The clearest evidence that this is not a theoretical risk is a case USADA published. On March 8, 2018, USADA announced that UFC athlete Ion Cutelaba “has accepted a six-month sanction after declaring the use of an alternative therapeutic treatment that is prohibited under certain routes of administration” [5]. He had declared ozone therapy on his doping control paperwork during out-of-competition tests in October 2017. USADA then asked for details of the route of administration, and, in USADA’s words, “Cutelaba’s physician subsequently provided documentation indicating that the treatment was administered on October 3, 2017, and October 17, 2017, in a prohibited manner, as it involved a blood transfusion” [5].

Three things in that account are worth carrying forward. The athlete declared the treatment and, by USADA’s account, was unaware of the violation, which earned a reduction from the standard two-year period to six months [5]. The route of administration, not the substance, decided the case. And the evidence that settled it came from his own physician’s records, which is a reminder that a clinic’s paperwork becomes the athlete’s paperwork.

What clinic pages tell athletes

Athlete marketing is a visible part of how EBO2 is sold, and our directory lets us measure it rather than assert it. As of October 4, 2026, of the 174 clinics whose EBO2 page our research pass could read, 26 have at least one saved paragraph that mentions athletes and also mentions EBO2, EBOO, or ozone. The phrasing in those paragraphs runs to faster recovery, reduced exercise-induced inflammation, better oxygen delivery to muscle, and performance optimization, sometimes alongside a recommended cadence of sessions per year for people under heavy physical load. Using the same method, 43 of the 174 have a paragraph pairing “performance” with the procedure and 75 have one pairing “recovery” with it. We name no clinic in connection with a benefit claim; the aggregate below shows the categories of condition claim across the whole directory.

None of the pages we read cited a study in athletes, because, as the next section sets out, there is none to cite. Ozone therapy is not FDA-approved for any medical use, and federal device labeling rules state that ozone “is a toxic gas with no known useful medical application in specific, adjunctive, or preventive therapy” [10]. A claim on a clinic’s page is a claim, and our clinic directory records what each one states so you can compare it against the research record yourself.

What the research closest to this question measured

Our library holds no study of EBO2 in athletes, in any sport, at any level, and no study of EBO2 with a performance or recovery outcome of any kind. Two studies sit closest to the question, and it is worth being precise about what each one did.

The cyclists trial reported higher peak power and a lower fatigue score after the ozonised-oil condition, and faster lactate decline, with no difference in heart rate [7]. It is a single-centre study of 15 men measuring the hours after a laboratory fatigue protocol, and the intervention is a massage oil.

The horse study reported that the antioxidant marker rose by three days after treatment and was no longer measurable at 14 days, with no change in the reactive-oxygen marker, and no abnormal blood counts or clinical signs during the study [8]. Its authors also wrote the sentence most relevant to an athlete reading it: “the Paris Agreement prohibits the re-administration of blood in racehorses; thus, application of OAHT to this group is currently limited” [8]. The one study that ozonated blood in a performance animal concluded that the sport’s own blood rule kept it out of competition animals.

Recovery with a larger evidence base behind it

For contrast, consider what the recovery literature looks like when it is large. A 2025 systematic review followed PRISMA methods across 41 randomized or crossover trials of post-exercise recovery in soccer players of both sexes and all levels, and grouped them into categories including active recovery, cold-water immersion, compression garments, sleep and naps, and nutritional interventions. It reported that cold-water immersion consistently improved jump performance and perceptions of fatigue, soreness, and wellbeing, with positive but more variable findings for active recovery, compression, sleep interventions, and nutritional supplementation, and it flagged heterogeneity in methods and outcomes as a limit on generalizing [9]. That is the shape of an evidence base: dozens of trials, named outcomes, stated limits. The ozone-and-performance literature is one massage-oil trial and ten horses.

Questions to ask before you book

• Which anti-doping code applies to me, and have I asked that organization, in writing, about this specific procedure by its full description rather than by its brand name?
• What total volume of fluid is returned to my circulation in a session, and over what period? The number matters because USADA’s statement of the rule turns on 100 mL per 12 hours outside hospital, surgical, and diagnostic settings [4][6].
• Will the clinic give me the complete treatment record, including the device, the ozone concentration, the blood volume processed, and the anticoagulant used? In the one published sanction, the physician’s records decided the outcome [5]. The transparency block below shows how many clinics even name their device or say who supervises a session.
• Is there a published study in athletes that the clinic can name, with a citation that can be checked against the research library or PubMed?
• What is the full course being recommended and what does it cost over a season? The block below shows what clinics across our directory recommend and sell.
• Who is physically present during the session, and what is the plan if something goes wrong? Our guide to side effects and safety and our record of adverse events by route set out what has been reported after ozone procedures.

What we could not verify

• Whether EBO2 is prohibited, permitted, or requires a Therapeutic Use Exemption in any particular sport. No anti-doping organization we read names EBO2 or EBOO. Only an athlete’s own anti-doping organization can answer for a given case, and this guide does not answer it.
• The Prohibited List itself. WADA’s website refused our automated requests for the 2026 and 2027 Lists and the 2026 explanatory note, returning a bot challenge rather than the documents, and the anti-doping agency pages we could read summarise the List rather than reproduce it. The rule wording in this guide is as NADA, the Athletics Integrity Unit, and USADA publish it [1][2][3][4][6]. We could not check WADA’s own clause wording or numbering, whether either edition names ozone therapy or ultraviolet treatment, or how the List classes these methods when a sanction is calculated.
• Major League Baseball’s Joint Drug Prevention and Treatment Program document was not read directly for this guide, so the statements about league rules here rest on sports reporting [11][13] rather than on our own reading of the program text.
• Whether any athlete other than the 2018 UFC case has been sanctioned in connection with ozone therapy. We found no other published decision, which is not the same as there being none.
• What the 26 clinics counted above mean by recovery or performance claims in clinical terms. We counted paragraphs in pages they published; we did not ask the clinics, and we did not evaluate the claims.
• Whether ozonised massage oil and ozonated blood act by any shared mechanism. The two studies above used different routes and measured different things, and neither tested the other’s method.

How this guide was made

This guide draws on 13 sources: three anti-doping organizations’ pages on the WADA Prohibited List (NADA’s, the Athletics Integrity Unit’s, and USADA’s), three further USADA publications, three peer-reviewed papers, one federal regulation, and three news reports of a public announcement by an athlete. The counts of athlete, performance, and recovery marketing come from our own directory of 177 US clinics and the saved page text behind it, read between September 28, 2026 and October 4, 2026, with the denominator of 174 readable EBO2 pages stated wherever a count appears; the blocks below are computed from that dataset and from our study library at build time. Drafting used AI tools. A human editor has not yet checked this guide claim by claim against its sources. No clinical reviewer has signed off on this page yet.