Fact Check-No evidence oxygen or hydrogen peroxide kills or treats cancer cells

Social media users are sharing claims that rubbing hydrogen peroxide onto the skin can treat cancer and that oxygen can kill cancer cells. These claims are not supported by evidence, an expert told Reuters, explaining that the posts “conflate” what might happen in a cell culture with “efficacy in treating a cancer in humans.”

Examples of posts claiming that applying hydrogen peroxide will kill cancer cells can be seen (here) and (here).

Related posts that include undated video claim that increasing oxygen in the body will destroy tumors, with some users advising the use of hydrogen peroxide rubbed into the skin to increase blood oxygen (here), (here) and (here).

While applying hydrogen peroxide to the skin might raise local oxygen levels slightly, an expert told Reuters Fact Check, it will not penetrate far enough into the body to reach most tumors, and there is no evidence that it would make a difference.

“Neither hydrogen peroxide nor oxygen has undergone the rigorous scrutiny and testing needed to prove that these therapies can treat cancer or kill cancer cells,” Tyler Johnson, a clinical assistant professor of oncology at Stanford Medicine, said via email. Without such evidence, “we have no confidence that these therapies are helpful.”

Specifically, rubbing hydrogen peroxide on the skin, which is typically used to treat minor cuts (here), will not kill cancer cells, Johnson said. While application of hydrogen peroxide can reach the bloodstream, he explained, it will not reach to a tumor far enough to have any helpful effect – in fact, "large amounts of ingested hydrogen peroxide are known to be toxic and cause internal burns."

The American Cancer Society published a review of “questionable methods of cancer management” known as “hyperoxygenating” agents and recommended against using them as alternatives to standard cancer treatments (here).

“The most highly touted ‘hyperoxygenating’ agents are hydrogen peroxide, germanium sesquioxide, and ozone,” the review explains. “Although these compounds have been the subject of legitimate research, there is little or no evidence that they are effective for the treatment of any serious disease, and each has demonstrated potential for harm.”

The U.S. Food and Drug Administration (FDA) also finds no medical benefit and potential harm in devices that produce ozone, a gas formed of three oxygen atoms (here).

One approach to raising oxygen levels in tumors that is used in conjunction with radiation or chemotherapy has shown some promise, according to the National Cancer Institute. The use of hyperbaric oxygen (HBO) to increase oxygen levels in cancer cells “may make them easier to kill with radiation therapy and chemotherapy," the group writes, and is still being investigated (here).

“As oncologists we will only claim that a drug works once it has been subjected to a series of increasingly rigorous tests,” Johnson said. “That must demonstrate under the most precise scrutiny that a drug both works at treating cancer and is safe.”

In a 2012 review of existing research, scientists at the University of Bergen, in Norway, concluded that HBO is likely safe, that there is no evidence HBO might stimulate tumor growth, and there is some evidence that it might inhibit growth of specific tumor types though more study is needed: “… there is evidence that implies that HBO might have tumor-inhibitory effects in certain cancer subtypes, and we thus strongly believe that we need to expand our knowledge on the effect and the mechanisms behind tumor oxygenation.” (here)


No evidence. There is no evidence that rubbing hydrogen peroxide on the skin, consuming it, or using other unproven methods to increase oxygen in the body will have an effect on cancer cells.

This article was produced by the Reuters Fact Check team. Read more about our work to fact-check social media posts (here).