Ozone gas applied through nebulization as adjuvant treatment for lung respiratory diseases due to COVID-19 infections

Background: severe COVID-19 and the search for adjuvant respiratory support

During the early phase of the COVID-19 pandemic, clinicians faced patients whose lungs became inflamed and congested as the SARS-CoV-2 virus took hold, sometimes progressing to pneumonia. With no established antiviral routine at the time, researchers looked at whether adding other supportive measures to standard care might help patients clear the infection and recover more quickly. Ozone gas has long been studied for its disinfectant and oxidative properties, and this trial set out to test whether delivering ozone directly to the airways, alongside conventional treatment, could support recovery in people with symptomatic COVID-19.

Study design: a small randomised trial of nebulised ozone

The study was a prospective randomised controlled trial carried out at a single centre in Turkey between August and September 2020. Thirty patients with confirmed, symptomatic COVID-19 were randomly divided into two groups of fifteen. One group received standard COVID-19 treatment alone. The other group received the same standard treatment plus ozone delivered by nebulisation, in which ozone gas was passed through distilled water and olive oil so that it could be inhaled into the lungs. The researchers then compared the two groups on measures such as the time taken to return a negative PCR test, changes in the inflammatory marker C-reactive protein (CRP), and length of hospital stay.

Findings: faster PCR negativity and inflammatory improvement in the ozone group

The patients who received nebulised ozone in addition to standard care tended to improve on the measures the researchers tracked. A larger proportion of the ozone group returned a negative PCR test within the study window compared with the group on standard care alone, and more of them showed improvement in C-reactive protein, a marker of inflammation. The authors also reported a shorter hospital stay in the ozone group. Because the trial was small, these differences should be read as early, exploratory signals rather than definitive proof.

What the authors concluded

The authors concluded that adding ozone inhalation to standard treatment appeared, in their data, to reduce the rate of pneumonia and to help patients respond faster and reach PCR negativity sooner. They presented nebulised ozone as a potential adjuvant, that is, a supportive addition to conventional care, and called for larger studies to confirm whether the approach offers a genuine benefit.

Limitations of this study

This was a very small trial, with only thirty patients in total and fifteen in each group, which limits how much confidence can be placed in the results and makes chance findings more likely. It was conducted at a single centre over a short period early in the pandemic, when standard COVID-19 care was still evolving, and the follow-up was short. The trial does not appear to have used blinding, so knowledge of who received ozone could have influenced how outcomes were assessed. The outcomes reported are largely surrogate measures, such as PCR results and blood markers, rather than long-term clinical recovery. Ozone therapy here is studied only as a complementary, adjuvant measure alongside standard medical treatment; it is not a cure for COVID-19 and is not a substitute for conventional care or vaccination. Anyone considering ozone therapy should do so under qualified medical supervision.