Three reasons why I think vitamin C can cancel out at least some of the effects of ozone therapy:
1. Personal experience
2. Reports of others who felt like they have overdosed on ozone. Their reactions were immediately stopped by the administration of vitamin C.
3. Recommendations of some ozone associations not to mix antioxidants with ozone therapy
In my opinion it’s best to do vitamin C and ozone therapy on alternate days. If that’s not possible, then to at least space them apart by a few hours.