Fact Check

By Reuters Fact Check

7 Min Read

Topical antiseptics such as hydrogen peroxide, iodine, or a combination of the two are not safe to inhale and not proven to treat respiratory infections, contrary to social media claims that breathing in these liquids is a good idea.

Both hydrogen peroxide and iodine solutions have been used as a mouth rinse to reduce numbers of oral bacteria and viruses, but experts say that inhaling or nebulizing them has not been tested in high doses because they have the potential to damage tissue and to be poisonous.

Still, social media users are sharing a video that claims using a nebulizer to make a vapor from a mixture of hydrogen peroxide and iodine can treat respiratory infections like sore throat.

A Facebook video with more than 14,000 shares at the time of writing claims that combining "the pathogen killing potential" of 3% hydrogen peroxide with iodine in a nebulizer will create a "super oxygenated system" that is "coating your entire upper respiratory tract" when breathing it in (here). Versions of the clip have been shared online since at least October 2021 (here).

Claims that inhaling hydrogen peroxide would treat respiratory illnesses such as COVID-19, flu and pneumonia date to at least 2021, when Reuters reported that medical professionals "strongly" advise against the unproven home remedy (here).

Inhaling hydrogen peroxide does not treat general illnesses and can instead complicate "the course of any successful treatments," Panagis Galiatsatos, M.D., an associate professor at Johns Hopkins Bayview Medical Center, told Reuters at the time.

The Asthma and Allergy Foundation of America has also warned against inhaling hydrogen peroxide from a nebulizer machine, which is normally used to turn liquid asthma medicine into a mist inhaled through a mask or mouthpiece (here).

Hydrogen peroxide can be toxic if ingested, inhaled, or exposed to the eyes, and inhaling the household-strength hydrogen peroxide (3%) recommended in the video can cause respiratory irritation, according to the U.S. Agency for Toxic Substances and Disease Registry (here).

Both hydrogen peroxide and iodine solutions are used on the skin, usually to prevent infection of minor cuts and scrapes (here). And both can be used in mouthwashes to reduce oral bacteria (here ), (here).

Evidence from studies of accidental inhalation shows that hydrogen peroxide can damage tissue and iodine can be toxic.

A safe concentration of hydrogen peroxide in the air, for example, is one part per million, or 0.0001% (here), (here) but the concentration needed to kill viruses or bacteria is much higher.

"If we’re speaking about stuff that kills microorganisms, that's like 3% - huge difference," Dr. Naftali Kaminski, chief of pulmonary, critical care and sleep medicine at the Yale School of Medicine, told Reuters. "Nebulizing it is terrible, it's really dangerous because when it hits mucosal surfaces, it will kill cells, cause inflammation."

Encouraging the use of iodine in a nebulizer dates to at least 2020, as the U.S. Food & Drug Administration (FDA) issued a warning letter to a website selling iodine solution while claiming it would treat COVID-19 at the time (here).

The dangers of inhaling vaporized iodine include increased pulmonary flow resistance, decreased ventilation rates and irritation to mucous membranes, according to the California Department of Justice Bureau of Forensic Services (here). Specifically, iodine can irritate the lungs and higher exposures "may cause a build-up of fluid in the lungs (pulmonary edema), a medical emergency," according to the Centers for Disease Control and Prevention (CDC) (see page 1-2) (here).

Dr. Sayantani Sindher, a clinical associate professor of medicine at Stanford Medicine (here), told Reuters that "the use of nebulizers to create at-home formulations is highly dangerous" and "there is a high risk of poisoning yourself."

The claim that combining hydrogen peroxide with iodine will create a "super oxygenated system" is also misleading, as "mixing hydrogen peroxide and iodine does create oxygen, but this does not mean that is safe or healthy," Sindher said. "While we need oxygen to survive, too much oxygen is toxic to your body and when oxygen is provided to patients it is mixed with other gases to create mixtures that are safe for use."

Studies on the combination of hydrogen peroxide and iodine in a nebulizer are needed to prove its safety, but "I don't think any institutional review board will approve a study like that because [of] the potential for injury," Kaminski said.

Ultimately, human lungs are only meant to breathe air, Kaminski said, so "never nebulize anything into your lungs" unless it received FDA approval and was proven to be safe.

False. There is no evidence that combining hydrogen peroxide and iodine in a nebulizer will treat respiratory symptoms, and the practice is potentially damaging and toxic, experts told Reuters.

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

Our Standards: The Thomson Reuters Trust Principles.