Ozone (also called trioxygen) is a molecule with 3 oxygen atoms. "Prolozone therapy" is the term for injection of ozone into joints and soft tissue. "Prolo" is part of the term because proponents claim that ozone stimulates growth and activity of fibroblasts and use ozone instead of dextrose or other types of proliferants. There are several claims made on sites that speak of prolozone. They are:
1. "Prolozone causes a 'permanent fix' in arthritis." There are no studies that are designed to show this or any large consecutive patient trials on any arthritis condition. There is an animal study that suggest an antiinflammatory effect of ozone in rheumatoid arthritis but no human work. Chang JD; Lu HS; Chang YF; Wang D Ameliorative effect of ozone on cytokine production in mice injected with human rheumatoid arthritis synovial fibroblast cells.Rheumatol Int (Germany), Dec 2005, 26(2) p142-51. This does not mean that ozone is not helpful for arthritis. Anecdotal evidence suggests it is, but that is all we have so far in humans.
2. "Italian clinics claim a 95% success rate in treating herniated discs with ozone injection." This is the only area in which human studies have been published so far in current literature search. In reality the best article I found showed 35% elimination of back pain and 45% with fewer episodes and pain improved in 85% total. Al-Jaziri AA; Mahmoodi SM Painkilling effect of ozone-oxygen injection on spine and joint osteoarthritis. Saudi Med J (Saudi Arabia), Apr 2008, 29(4) p553-7. This is about the same as other studies on other proliferants. Note also that the disc was injected and also the area were nerve roots exit and the space just outside the spinal canal (epidural space). Therefore we don't know which part of the injection appeared to help. One other study on ozone use was blinded and compared epidural injection with steroid to epidural injection with steroid and ozone and the latter was more helpful. Gallucci M; Limbucci N; Zugaro L; Barile A; Stavroulis E; Ricci A; Galzio R; Masciocchi C. Sciatica: treatment with intradiscal and intraforaminal injections of steroid and oxygen-ozone versus steroid only. Radiology (United States), Mar 2007, 242(3) p907-13. This does suggest some benefit of ozone in the epidural space.
3. "Ozone injection stimulates growth and activity of fibroblasts" Fibroblasts are the reparative cells for ligaments and tendons. There is no proof of this yet, but many solutions stimulate fibroblast growth and we need to wait on further studies on how it works.
In summary, there are suggested benefits of ozone with injection but studies are few at this point. There is no evidence thus far that suggests a better result with ozone use than other types of prolotherapy. Note that for complex cases with many areas of involvement ozone use may be laborious and limit the area that can be treated at one time. Cost versus benefit has not been explored.