As an emergency department doc, back in the day, we used it to clean up maggot-infested wounds in homeless people. It fizzed away, killed the maggots and left behind water.
The immune system uses it as an intracellular killing mechanism, but it is produced, packaged and used inside the cell. I'm not aware of any evidence that taking H2O2 orally will change anything inside a cell. As it spontaneously reverts back to water and oxygen, I suggest that your friend who ingests dilute amounts is likely to be wasting his time.
andy |