Dear Dr. Walt,
I’ve heard that drinking a small amount of hydrogen peroxide with water can kill bacteria in the urinary tract and is good for health in general.
—Vigorous in West Virginia
I heartily advise against taking any form of hydrogen peroxide (H2O2) by mouth. Here’s some background on my opposition.
First of all, a dilute form of H2O2 (3% H2O2, 97% water) is sold in pharmacies, but is only recommended for external use—for example, to disinfect minor cuts.
There have been many, many cases of accidental ingestions of the 3% solution, particularly by children, which result in significant gastrointestinal irritation of the stomach.
Also, dentists often recommend 3% H2O2 as a safe and effective mouth rinse for debriding the oral cavity.
A stronger, 35% H2O2 is sold online and in some health food stores and often labeled “food grade.”
It is promoted for a wide range of medical indications, including the treatment of conditions including AIDS, cancers, and emphysema.
You should know that the FDA has never approved H2O2 to be taken internally and considers hydrogen peroxide at the 35% percent strength dangerous, even if handled according to the manufacturer’s directions (which typically involve dilution).
So, because oral H2O2 has never been proven effective, and because it is possibly unsafe, I cannot recommend it.