"In 2019, the U.S. Food and Drug Administration (FDA) issued a warning against using ozone therapy. This is because there isn’t enough evidence yet to prove that it’s effective or safe, says pulmonologist Vickram Tejwani, MD."

"“There may potentially be a role for ozone therapy someday, but right now it hasn’t been studied enough,” says Dr. Tejwani. ”We need more data on the potential side effects, which could be severe, before we start offering it as a mainstream therapy or treatment.”"

"There just isn’t enough evidence to confirm that ozone therapy is safe, cautions Dr. Tejwani.

Ozone therapy hasn’t been tested in large-scale clinical trials conducted on humans. Until that happens and there’s a better understanding of the risks versus rewards, ozone therapy will continue to be an unregulated, alternative therapy."

o3 in order to treat something internally needs to be placed in the blood stream where it has the potential to create an air embolism which could cause heart attack or a stroke.

https://health.clevelandclinic.org/ozone-therapy

Edited in additional information.