Hydrogen peroxide is not a cure for any infectious disease, including COVID-19. There is no evidence that hydrogen peroxide is a cure for the common cold, COVID-19, HIV, cancer, or any other disease. Ingesting hydrogen peroxide is dangerous. It is not meant for human consumption in any form and can be dangerous to human health, especially at high concentrations.

Inhaling the substance — even when diluted to 3% — can lead to a burning nose, throat, and chest. It can cause respiratory irritation, and eye burning and irritation. Inhaling it in larger quantities can cause even more harmful outcomes. If the substance is more concentrated, say 10% or more, inhaling it can cause bronchitis, severe pulmonary irritation, pulmonary edema (excess fluid in your lungs), and severe shortness of breath. Even inhaling hydrogen peroxide at very low doses (eg. 0.1%) would still not be helpful against any disease and could still cause harm, especially in large quantities.

Drinking a small quantity (3% hydrogen peroxide) can result in vomiting, nausea, and gastric distestation (enlargement of the stomach). Drinking more of it can cause worse outcomes. Ingesting more concentrated forms, such as 35% hydrogen peroxide, can lead to severe gastrointestinal burning and erosion, ulceration and perforation, and death. 

A recent trend that has been circulating on various social media platforms involves people inhaling hydrogen peroxide vapors as a potential treatment or cure for COVID-19. This action is not only dangerous, it has also been tried as a potential cure for a variety of other illnesses, including the common cold and HIV. 

Social media posts are recommending that people use asthma nebulizers to inhale hydrogen peroxide. Inhaling hydrogen peroxide could be particularly dangerous for people with asthma.

Through putting the liquid into a nebulizer and inhaling it, people may be unknowingly damaging their lungs through their cells and cell membranes and potentially even damaging their DNA.

Further, this treatment can cause the build-up of fluid in the lungs, also called a pulmonary edema. In addition to the potential medical diagnoses listed above, inhaling this liquid would likely worsen already irritated lungs in people infected with COVID-19.

For this reason and more, many physicians and medical groups have denounced this practice and are urging people to stop any attempts to inhale the substance. It is always best to speak to a medical professional before beginning any new treatments or practices but in the case of hydrogen peroxide and nebulizers, this action should be avoided at all costs.