Gwyneth Paltrow says rectal ozone therapy was 'very helpful.' The FDA says it has no medical use.

• Asked to name the "weirdest wellness thing you've done," Gwyneth Paltrow said rectal ozone therapy.
• She told "The Art of Being Well" podcast it was "very helpful." 
• Ozone therapy is not approved by the FDA.

Gwyneth Paltrow said that she has had rectal ozone therapy in an interview with the podcast "The Art of Being Well."

When asked by host Dr. Will Cole to name the "weirdest wellness thing you've done," the Goop founder said on the show released Monday: "I have used ozone therapy rectally," adding: "it's pretty weird."

Dr. Cole chimed "it's pretty weird," and joked that it would make for "a good Friday night."

Paltrow said she found the treatment "very helpful," but did not detail any benefits or what the therapy was used for. 

Ozone therapy is not approved by the FDA

Ozone is a type of oxygen, and the therapy is based around the idea that higher levels of oxygen in the body may be able to boost the immune system and promote healing, pulmonologist Dr. Vickram Tejwani told Cleveland Clinic.

Ozone therapy can be given in a variety of ways: including being applied to the skin, blown into the body vaginally or rectally — like in Paltrow's case — ingested, mixing with blood in an IV, and injected into the muscles.

Ozone therapy isn't approved by the FDA, which said in its Code of Federal Regulations updated in January that ozone is a toxic gas with no useful medical application, whether preventative, supplementary, or as a treatment. 

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

The FDA said that inhaling the gas can irritate the lungs and cause pulmonary edema — where a person struggles to breathe because of fluid in the lungs.