The other day, a website called ConsumerLab.com sent some big ripples through the dietary-supplement industry--and triggered a frantic phone call from my producer on NBC's Today show. She wanted to know about the results of a study in which scientists at the website tested the contents of several over-the-counter products, comparing what they found inside with the ingredients listed on the label.
It wasn't, to put it mildly, a stellar day for the booming supplement industry, whose U.S. sales have ballooned to more than $14 billion a year. ConsumerLab, a small, independent laboratory in White Plains, N.Y., is trying...