Up to 58 percent of physicians in the U.S. regularly prescribe placebos, according to a survey of 679 rheumatologists and general internists conducted by Jon C. Tilburt of the National Institutes of Health and his colleagues. Even though placebos may contain no active ingredients, many ailments still respond positively to them [see “The Placebo Effect,” by Walter A. Brown; Scientific American, January 1998].

Percent of physicians who believe prescribing placebos is ethical: 62

Percent who have prescribed placebos that were:

Over-the-counter painkillers: 41

Vitamins: 38

Antibiotics: 13

Sedatives: 13

Saline: 3

Sugar pills: 2

Percent who told patients that the treatment is:

Potentially beneficial but not typically used for their condition: 68

Medicine: 18

A placebo: 5

SOURCE: British Medical Journal, online October 23, 2008