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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. It may even be dangerous. There have been reports of patient deaths from this method.

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.

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.

In conventional medicine and first aid, a dilute solution of hydrogen peroxide is applied to skin wounds. As an alternative therapy, hydrogen peroxide is usually taken by mouth or injected into a vein. Some practitioners promote it for use rectally, vaginally, as a nasal spray, and as eardrops. It is often used to soak affected parts of the body. The stronger solutions (about 35 percent) recommended by alternative medicine practitioners are sold in some health food stores.

The frequency of treatments varies widely, from three times a day over several weeks to once a week for several months.

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." 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?

Available scientific evidence does not support claims that increasing oxygen levels in the body will harm or kill cancer cells. It is difficult to get the oxygen level around the cancer cells in the middle of a tumor higher 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 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 tumors to cancer in humans remains unproven.

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."

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 very concentrated. It contains 35 percent hydrogen peroxide, a concentration that is more than ten times stronger than the 3 percent peroxide approved for use on the skin. Food grade hydrogen peroxide is approved by the FDA to clean food surfaces and for certain bleaching 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, and even death. If it gets in the eyes, it can damage the corneas and cause blindness. Direct skin contact with food grade hydrogen peroxide can cause blistering or burns, and breathing its vapors can also be harmful.

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. Some 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."

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.

Additional resources

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 ( or ordered from our toll-free number (1-800-ACS-2345).

Guidelines for Using Complementary and Alternative Therapies

Dietary Supplements: How to Know What Is Safe

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

Complementary and Alternative Methods for Cancer Management

Placebo Effect

Learning About New Ways to Treat Cancer

Learning About New Ways to Prevent Cancer


American Cancer Society. Questionable methods of cancer management: hydrogen peroxide and other 'hyperoxygenation' therapies. CA Cancer J Clin. 1993;43:47-56.

Barrett S. "Miraculous recoveries". Quackwatch Web site. Accessed at: Updated October 18, 2000 on Accessed June 11, 2008.

Cassileth B. The Alternative Medicine Handbook: The Complete Reference Guide to Alternative and Complementary Therapies. New York, NY: W.W. Norton; 1998.

Cina SJ, Downs JC, Conradi SE. Hydrogen peroxide: a source of lethal oxygen embolism. Case report and review of the literature. Am J Forensic Med Pathol. 1994;15:44-50.

Ernst E. A primer of complementary and alternative medicine commonly used by cancer patients. MJA 2001; 174: 88-92

FDA warns consumers against drinking high-strength hydrogen peroxide for medicinal use. FDA News. July 27, 2006. US Food and Drug Administration. Accessed at: on June 11, 2008.

Gatenby RA, Gillies RJ. Why do cancers have high aerobic glycolysis? Nat Rev Cancer. 2004 Nov;4(11):891-9.

Green S. Oxygenation therapy: unproven treatments for cancer and AIDS. Quackwatch Web site. Accessed June 11, 2008.

León OS, Menéndez S, Merino N, Castillo R, Sam S, Pérez L, Cruz E, Bocci V. Ozone oxidative preconditioning: a protection against cellular damage by free radicals. Mediators Inflamm. 1998;7:289-294.

Loughlin KR, Manson K, Cragnale D, Wilson L, Ball RA, Bridges KR. The use of hydrogen peroxide to enhance the efficacy of doxorubicin hydrochloride in a murine bladder tumor cell line. J Urol. 2001;165:1300-1304.

Oxygen therapies. Memorial Sloan-Kettering Cancer Center Web site. Accessed June 11, 2008.

Sherman SJ, Boyer LV, Sibley WA. Cerebral infarction immediately after ingestion of hydrogen peroxide solution. Stroke. 1994;25:1065-1067.

Schultz S, Häussler U, Mandic R, Heverhagen J, et al. Treatment with ozone/oxygen-pneumoperitoneum results in complete remission of rabbit squamous cell carcinomas. Int J Cancer 2008; 122(10): 2360-7.

Watt BE, Proudfoot AT, Vale JA. Hydrogen peroxide poisoning. Toxicol Rev. 2004;23:51-57.

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: 11/01/2008
Last Revised: 11/01/2008