Chronic hepatitis C virus infection has a lot of similarly to ME/CFS: it is caused by a virus, and has much of the symptoms of ME/CFS. The following study on ozone treatment for hepatitis C virus is interesting, as the treatment reduced viral loads, and significantly improved symptoms such as fatigue: Preliminary Results of Ozone Therapy as a Possible Treatment for Patients with Chronic Hepatitis C (full paper here) Patients with chronic hepatitis C infection were given ozone therapy sessions (in the form of major autohemotherapy) three times per week. Around half the patients were given a total of 30 thrice weekly sessions of ozone therapy, and the other half were given 60 thrice weekly ozone treatment sessions. There was also a control group which was not give ozone. After 30 such ozone treatments (2.5 months), 25% of patients no longer had hepatitis C virus RNA in their blood. After 60 ozone treatments (5 months), 44% of patients no longer had hepatitis C virus RNA in their blood. There was also a significant reduction in chronic hepatitis C virus symptoms such as fatigue, abdominal pain, arthralgia, and loss of libido. The levels of the liver enzymes ALT and AST normalized in 58% and 60% respectively of the 30 and 60 session patients. The major autohemotherapy ozone treatment used in this study is described here. Essentially, autohemotherapy involves drawing some blood from the patient, injecting medical grade ozone gas into that blood, and then intravenously infusing this blood back into the patient. Major autohemotherapy requires trained professionals in a clinical setting. Rectal insufflation of ozone (putting a small amount of ozone gas into the rectum) is considered to be almost (95%) as effective as major autohemotherapy. Ref: 1 But rectal insufflation of gas can easily be self-administered at home, if you have a machine that makes ozone gas (which cost around $1,000 for a medical grade device). Thus ozone therapy at home, in the form of rectally administered ozone, would be quite feasible, and easy to do. There seems to be very little online about ME/CFS patients trying ozone treatment, and certainly no studies on this that I could find. That could of course be because it is not particularly helpful for ME/CFS.