JENNIFER Buettner was taking care of her young niece when the idea struck her. The child had a nagging case of hypochondria, and Mrs Buettner's mother-in-law, a nurse, instructed her to give the girl a tablet. "She told me it was the most benign thing I could give," Mrs Buettner said. "I thought, why give her any drug? Why not give her a placebo?"

Studies have repeatedly shown that placebos can produce improvements for many problems such as depression, pain and high blood pressure, and Mrs Buettner reasoned that she could harness the placebo effect to help her niece.

She sent her husband to the pharmacy to buy placebo pills. When he came back empty-handed, she said: "It was one of those 'aha!' moments when everything just clicks."

Mrs Buettner, 40, who lives in Maryland with her husband, seven-month-old son and 22-month-old twins, envisioned a children's placebo tablet that would empower parents to do something tangible for minor ills and reduce the unnecessary use of antibiotics and other medicines.

With the help of her husband, Dennis, she founded a placebo company and, without a hint of irony, named it Efficacy Brands. Its chewable, cherry-flavoured dextrose tablets, Obecalp (placebo spelt backwards), go on sale on Sunday at the Efficacy Brands website. Bottles of 50 tablets will sell for $US5.95 ($A6.20). The Buettners have plans for a liquid version too.

Because they contain no active drug, the pills will not be sold as a drug under Food and Drug Administration rules. They will be marketed as dietary supplements, meaning they can be sold at groceries, pharmacies and discount stores without a prescription.

But some experts question the premise behind the tablets. "Placebos are unpredictable," said Howard Brody, a medical ethicist and family physician at the University of Texas Medical Branch at Galveston. He said there was no way to predict who would respond.

"The idea that we can use a placebo as a general treatment method strikes me as inappropriate," Dr Brody said.

Mrs Buettner does not spell out the conditions that her pills could treat. As a parent, she said, "you'll know when Obecalp is necessary".

Franklin Miller, a bioethicist at the National Institutes of Health, said he was sceptical. "As a parent of three now-grown children, I can't think of a single instance where I'd want to give a placebo," he said.

Much of the power of the placebo effect seems to lie in the belief that it will work, and some experts question whether this expectation can be sustained if the person giving it knows it is a sham.

Most clinical trials that have shown benefits from placebos are double-blinded: neither the recipient nor the giver knows that the pills are fake.

Dr David Spiegel, a psychiatrist who studies placebos at the Stanford School of Medicine, said conditioning children to reach for relief in a pill could make them easy targets for quacks and pharmaceutical pitches later.

NEW YORK TIMES