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Oxygen Therapy

Other common name(s): oxygenation therapy, hyperoxygenation, bio-oxidative therapy, oxidative therapy, ozone therapy, autohemotherapy, hydrogen peroxide therapy, oxidology, oxymedicine, germanium sesquioxide

Scientific/medical name(s): O3 (ozone), H2O2 (hydrogen peroxide)


Oxygen therapy introduces substances into the body that are supposed to release oxygen. The extra oxygen is believed to increase the body's ability to destroy disease-causing cells. Two of the most common compounds used in oxygen therapy are hydrogen peroxide and ozone—a chemically active form of oxygen. This type of treatment is different from the common medical uses of oxygen, which involve increasing the amount of oxygen gas in inhaled air. It is also different from hyperbaric oxygen, which involves the use of pressurized oxygen gas (see our document on Hyperbaric Oxygen Therapy).


Available scientific evidence does not support claims that putting oxygen-releasing chemicals into a person's body is effective in treating cancer. Some types of oxygen treatment may even be dangerous; there have been reports of serious illness and death from hydrogen peroxide. Ozone is a strong oxidant that can damage cells, and has also caused deaths.

Use of ozone or peroxide in small amounts under controlled conditions for treating limited parts of the body has shown some success in mainstream medical research studies.

How is it promoted for use?

Different varieties of oxygen therapy are promoted as alternative treatments for dozens of diseases, including certain types of cancer, asthma, emphysema, AIDS, arthritis, heart and vascular diseases, multiple sclerosis, and Alzheimer’s disease.

Some supporters claim that cancer cells thrive in low-oxygen environments. They believe adding oxygen to the body creates an oxygen-rich condition in which cancer cells cannot survive. Supporters of this type of treatment claim that it increases the efficiency of all cells in the body and increases energy, promotes the production of antioxidants, and enhances the immune system.

A few proponents believe that soaking an affected body part can cause tumors to separate from the body so that a cancer can be “wiped away.”

What does it involve?

Ozone gas may be mixed with air or liquids and introduced into the body. It may be given under pressure into the rectum, vagina, or other body opening or injected into a muscle or under the skin. In an approach called autohemotherapy, the practitioner uses a special device to force ozone into a pint of blood that has been drawn from the patient. The blood is then returned to the patient's body.

Another alternative therapy approach involves hydrogen peroxide taken by mouth or injected into a vein. Some practitioners promote it for use rectally, vaginally, as a nasal spray, as a soak, and as eardrops. Very strong solutions (about 35%) recommended by alternative medicine practitioners are sold in some health food stores. By contrast, mainstream medicine may use a dilute solution (usually 3%) of hydrogen peroxide to clean skin wounds.

The frequency of these types of oxygen treatments varies widely, from three times a day over several weeks to once a week for several months. Some practitioners or sellers also promote “oxygenated” pills, mixtures, or liquids, which can be used at home.

What is the history behind it?

The history of putting oxygen-releasing substances into the body follows several tracks. Interest in ozone dates back to the mid-1800s in Germany, where it was claimed to purify blood. During World War I, doctors used ozone to treat wounds, trench foot, and the effects of poison gas. In the 1920s, ozone and hydrogen peroxide were used experimentally to treat the flu.

One of the earliest accounts of the medical use of hydrogen peroxide was a short article by I.N. Love, MD, in 1888 in the Journal of the American Medical Association. Dr. Love described one case in which he felt hydrogen peroxide had been useful in removing pus from the nose and throat of a child with diphtheria, and also recommended using hydrogen peroxide for "cancer of the womb… as a cleanser, deodorizer, and stimulator of healing." Unlike most current articles in that prestigious journal, the 1888 report did not include details that would be required today, such as whether patients treated with peroxide lived longer than those receiving placebo, or even whether there was any evidence that peroxide caused cancers of the womb to shrink or disappear. In 1920, hydrogen peroxide injections were used to treat patients during an epidemic of viral pneumonia.

In 1919, William F. Koch, MD, a Detroit physician, proposed that cancer was caused by a single toxin and that the disease could be prevented or reversed by removing that toxin. To achieve this goal, Dr. Koch claimed he had developed glyoxylide, an oxygen compound that could be injected into patients’ muscles. Dr. Koch and his followers claimed that glyoxylide forced cancer cells to absorb oxygen, which helped to rid the body of the cancer-causing toxin. In 1942, the U.S. Food and Drug Administration (FDA) charged Dr. Koch with making false claims about glyoxylide. The courts upheld the accusations, and in 1963 the California Cancer Advisory Council reported that glyoxylide therapy had “no value in the diagnosis, treatment, alleviation, or cure of cancer.” Canadian researchers were also able to observe a doctor who tested glyoxylide on 9 people with cancer. All 9 died, and the Canadian researchers reported that afterward they got no further cooperation from the investigator. Later researchers were unable to confirm that glyoxylide ever existed, and studies by theoretical physical chemists showed that the chemical structure that Koch claimed to be glyoxylide cannot possibly exist. (Even so, a number of alternative medicine Web sites still promote glyoxylide as a cancer cure.)

During the 1930s, Otto Warburg, MD, a winner of the Nobel Prize in 1931 for his research on respiratory enzymes, discovered that cancer cells have a lower respiration rate than normal cells. He reasoned that cancer cells thrived in a low-oxygen environment and that increased oxygen levels might therefore harm and even kill them. Many of the beliefs held by oxygen therapy practitioners are based on Dr. Warburg’s theories concerning cancer, even though technical advances have since offered a great deal more information about how cancer cells really use oxygen. Even if more oxygen is available, it does not cause the cancer cell to switch back to normal oxygen use. And, a higher oxygen level does not seem to hurt cancer cells any more than it hurts healthy cells.

Much of the more recent use of hydrogen peroxide can be traced to Father Richard Wilhelm, a retired high school teacher and former Army chaplain. He claimed to have discovered the healing potential of hydrogen peroxide through acquaintance with a doctor who headed the Mayo Clinic's division of experimental bacteriology, Edward Carl Rosenow, MD. Wilhelm promoted drinking hydrogen peroxide for a host of human ailments.

What is the evidence?

Ozone and hydrogen peroxide are known to have properties of disinfection, much like chlorine bleach, and are often used to clean instruments or surfaces. They are used in careful concentrations to clean or disinfect wounds. Hydrogen peroxide is also used in the mouth by dentists.

Available scientific evidence does not support claims that increasing oxygen levels in the body will harm or kill cancer cells. It is difficult to raise the oxygen level around the cancer cells in the middle of a tumor because the blood supply tends to be poor. But there are differences in the way cancer cells use oxygen that may allow new treatments to better target cancer cells.

According to Dr. Stephen Barrett, who writes about health fraud, a researcher from the Dominican Republic claimed that his clinic had used ozone gas to cure thirteen people with cancer. An investigative news group later learned that two of the patients had died of cancer, three could not be found, two refused to be interviewed, three were alive but still had cancer, and in three cases it was not clear that the patients had actually ever had cancer.

Some researchers have studied hydrogen peroxide as an addition to radiation therapy. Although some patients appeared to benefit, many did not. Some laboratory tests have looked at the combined effects of hydrogen peroxide and certain chemotherapy drugs against cancer cells, but it is still too early to tell if this will be of any benefit. According to a review article in CA: A Cancer Journal for Clinicians, attempts to treat patients by injecting hydrogen peroxide directly into solid tumors or into the blood system have generally been ineffective. In one study, mice were injected with glucose oxidase (an enzyme that breaks down glucose, with one of the byproducts being hydrogen peroxide) bound to microspheres, a technique that caused hydrogen peroxide to be released directly at the tumor site. Mice that received injections lived longer than those that did not. The researchers in this study concluded that more research on the use of hydrogen peroxide with other anti-tumor drugs was needed.

In one 2008 study, some experimentally-induced tumors in rabbits disappeared without any treatment, but more disappeared after treatment with ordinary oxygen, and even more disappeared after ozone treatment. In this study, the oxygen and ozone were injected into the rabbits' abdomens (peritoneal space). However, the relevance of such animal-model tumors to cancer in humans remains unclear.

A 2001 review of ozone therapy concluded that "… few rigorous clinical trials of the treatment exist. Those that have been published demonstrated no evidence of effect… Until more positive evidence emerges, ozone therapy should be avoided."

Since that time, most of the medical studies of ozone in humans that have shown success have used ozone in carefully controlled amounts on limited areas of the body. For example, an Italian study of medical ozone looked at using it in a small area of the mouth. A few patients with osteonecrosis of the jaw showed improvement after antibiotic therapy, cleaning, and 3-10 days of 10-minute applications of liquid ozone to the area. (Osteonecrosis of the jaw is a rare but distressing complication of certain cancer treatments, involving damage to the bone.) Studies are underway looking at using ozone in limited areas of the body such as arthritic joints and spinal bones after failed back surgeries.

Oxygen therapies as unproven alternatives are promoted as cures for cancer and other serious illnesses, and are offered at clinics in Mexico, the United States, and Europe. Available scientific evidence does not support claims that oxygen therapies can cure cancer in humans.

Are there any possible problems or complications?

The medical literature contains several accounts of patient deaths attributed directly to putting oxygen-releasing substances into the body.

Hydrogen peroxide can be harmful if swallowed, especially the concentrated solutions sold in some health food stores. “Food grade” peroxide is a very strong corrosive solution. It contains 35% hydrogen peroxide, a concentration that is more than ten times stronger than the 3% peroxide approved for use on the skin. Food grade hydrogen peroxide is approved by the FDA to clean food surfaces and for certain bleaching and disinfecting tasks in food production. The FDA requires that any peroxide that might remain in food be broken down into oxygen and water before the food reaches the consumer. Drinking food grade hydrogen peroxide can cause vomiting, severe burns of the throat and stomach, trouble breathing, bleeding in the stomach or intestine, symptoms of stroke, and even death. As it absorbs from the stomach or intestine, it can sometimes form bubbles in the blood vessels and block blood flow to parts of the body or brain. If it gets in the eyes, it can damage the corneas and even cause blindness. Direct skin contact with food grade hydrogen peroxide can cause blistering or burns, and breathing its vapors can cause serious breathing problems up to 72 hours later. Ozone in gas form must be well controlled. Ozone is a strong oxidant capable of damaging cells, and inhaling it can inflame the lungs and tighten airways. This problem is much worse for people with asthma.

Hydrogen peroxide injections can have dangerous side effects. High blood levels of hydrogen peroxide can create oxygen bubbles that block blood flow and cause gangrene and death. Destruction of blood cells has also been reported after intravenous injection of hydrogen peroxide. A few people can also have serious allergic reactions to hydrogen peroxide. A 1993 review article also found some research evidence that too much oxygen in the body's tissues may damage genetic material and promote abnormal growth.

A 2001 review of ozone therapy warned that “The risks of ozone therapy are played down by its proponents. Yet, numerous reports of serious complications, including hepatitis, and at least five fatalities have been reported.” More recently, researchers have called for standard medical ozone treatments and research studies that are safer and less likely to cause serious illness and death. For example, they recommend avoiding direct injection of ozone or ozonated saline (saltwater) into the bloodstream, and suggest careful dosing to reduce the risks.

Women who are pregnant or breastfeeding should not use this method, as its possible effects on a fetus are unknown. Relying on this type of treatment alone and avoiding or delaying conventional medical care for cancer may have serious health consequences.

To learn more

More information from your American Cancer Society

The following information on complementary and alternative therapies may also be helpful to you. These materials may be found on our Web site (www.cancer.org) or ordered from our toll-free number (1-800-227-2345).

Dietary Supplements: What Is Safe?

The ACS Operational Statement on Complementary and Alternative Methods of Cancer Management

Complementary and Alternative Methods and Cancer

Placebo Effect

Learning About New Ways to Treat Cancer

Learning About New Ways to Prevent Cancer


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Note: This information may not cover all possible claims, uses, actions, precautions, side effects or interactions. It is not intended as medical advice, and should not be relied upon as a substitute for consultation with your doctor, who is familiar with your medical situation.

Last Medical Review: 12/26/2012
Last Revised: 12/26/2012