Using an enzyme called superoxide dismutase, human cells generate some hydrogen peroxide on their own in order to kill bacteria, Glaspy said. Hydrogen peroxide may still be of interest to cancer researcher s, though not as a cure in itself. An NCI spokesperson directed the AP to the agency’s guide for finding more reliable cancer resources. The National Cancer Institute, a government research office under the National Institutes of Health, told the AP that rubbing hydrogen peroxide on the skin is “an old claim,” and said it doesn’t have “any information supporting” it. It’s an extremely poor cancer drug that wouldn’t make it past the first stages of cancer drug development,” he said. “The idea that hydrogen peroxide is a cancer drug is a silly one.

The compound also isn’t much better at destroying cancer cells than normal, healthy cells, Glaspy said. And if someone were to drink or inject enough hydrogen peroxide to maintain a high concentration in their body, it would likely just kill them. John Glaspy, an oncologist and professor at the University of California, Los Angeles, School of Medicine, told the AP that hydrogen peroxide can’t be absorbed via the skin as Gerson suggests.