Basic biological and therapeutic effects of ozone Therapy in human medicine

Background

Ozone has a poor public reputation: as a lung irritant in smog and an industrial disinfectant, it is usually thought of as purely harmful. Yet for decades, clinicians in parts of Europe have used ozone therapeutically, dissolving small, precisely controlled amounts of the gas in blood or other biological fluids to treat a range of conditions. This chapter, written for the UNESCO-backed Encyclopedia of Life Support Systems, sets out to answer the question underpinning that practice: how can a strong oxidant like ozone produce a beneficial effect in the body at all, and what actually happens, biochemically, when it meets blood or tissue?

Study design

This is not a single clinical trial but a narrative reference chapter written by two ozone-therapy researchers based at the University of Siena, Italy. The authors bring together decades of biochemical and pharmacological research - much of it their own - on what occurs when ozone gas is dissolved in blood plasma or water. They describe the controlled delivery methods used in clinical practice, such as major autohaemotherapy, in which a small volume of a patient's blood is withdrawn, exposed to a precise, low concentration of ozone gas, and then reinfused. The chapter also draws on laboratory measures historically used to track ozone's downstream effects, including markers of lipid oxidation, antioxidant enzyme activity, and inflammatory signalling molecules.

Findings

When ozone dissolves in blood plasma it reacts almost instantly with polyunsaturated fatty acids and antioxidants already present in the fluid, rather than circulating through the body as ozone itself. This reaction generates a defined set of secondary molecules - chiefly hydrogen peroxide and specific lipid oxidation products - which the authors describe as the true "messengers" that diffuse into cells and trigger the body's response. These messengers were found to switch on antioxidant enzymes such as superoxide dismutase, glutathione peroxidase and catalase, and to prompt a modest, controlled release of growth factors and immune signalling molecules. Crucially, the authors describe this cascade as strictly dose-dependent: too little ozone produces no measurable effect, while excessive doses cause toxicity rather than benefit. Repeated exposure within this narrow therapeutic range appears to train the body's antioxidant defences over time, an effect the authors term adaptation to chronic oxidative stress.

What the authors concluded

The authors conclude that, within a carefully defined dose range, ozone behaves as a genuine pharmacological agent - in their words, "an extremely versatile drug" - rather than a simple disinfectant. They argue that this dose-dependent, biochemically defined mechanism explains why properly administered ozone therapy avoids the acute and chronic toxicity associated with uncontrolled ozone exposure, such as inhaling ozone as an air pollutant, and why it may help correct the chronic oxidative stress seen in a range of long-term health conditions.

Limitations of this study

This chapter is a narrative review and reference work, not a primary experimental study - it presents no new clinical trial or original patient data, and encyclopedia chapters of this kind are not peer-reviewed in the same way as journal articles. As a contribution built largely on the authors' own prior research, its conclusions reflect the perspective of one research group rather than an independent systematic review or meta-analysis of the wider literature. The exact year this chapter was compiled could not be independently confirmed from the available copy, and it predates more recent randomised trial evidence in specific disease areas. As with any complementary therapy, decisions about ozone treatment should always be made in conversation with a qualified practitioner.