Ozone therapy has possible mechanisms for treating ALS. A preclinical study in very small numbers of mTDP43 mice (which has yet to be peerreviewed) suggested benefits on motor function and survival (21,22); however, these benefits were not seen in mSOD1 mice (20). One verified “ALS reversal” occurred on a cocktail of alternative therapies including ozone (24); an association such as this does not prove causality. There have been no trials of ozone therapy in PALS. There may be potentially serious side effects associated with ozone therapy, depending on the dose (31). Based on all this, we support further investigation of ozone therapy in ALS cell or animal models, but we cannot yet recommend it as an ALS treatment.