Rhode Island-based retail pharmacy giant CVS is launching a program to require testing of all the vitamins and supplements it sells, aiming to make sure — and assure customers — that they contain what they say they do.

"To our knowledge, this is the first time that any national retailer is requiring all vitamins and supplements to undergo third-party testing, in order to be sold on our shelves," says CVS Senior Vice President George Coleman.

More than 1,400 vitamins and supplements from 152 brands have now undergone testing, CVS says.

The testing is performed by independent inspectors — not by CVS or the supplement makers themselves. It checks for contaminants and verifies that the contents listed on the labels are correct.

CVS says 7% of the products flunked, and were either pulled from the shelves or had to change their labels.

A leading researcher on supplements, Dr. Pieter Cohen of Cambridge Health Alliance and Harvard Medical School, praises the program, but adds, "We should have had this for the last 25 years."

It should long have been the norm, he says, "that if we go into CVS, and we purchase Vitamin D, what's listed on the label should be exactly what's in the pills."

But the lax regulation of supplements in the United States means there's no guarantee, he says.

Research by Cohen and others has found that many supplements contain unlisted ingredients and sometimes even dangerous drugs. The CDC estimates that supplements result in 23,000 emergency room visits in the U.S. every year.

While the new CVS testing program is an important step forward, Cohen says, he also hopes CVS will take "the next most appropriate step:" to reality-check the claims of health benefits — often based on very flimsy evidence — that supplements make on their bottles.

The company should decide that "no one can make claims on these supplement bottles unless they're supported by evidence in humans," he argues.

CVS operates nearly 10,000 pharmacies nationwide, and its supplement sales are part of a steadily growing industry worth an estimated $40 billion a year.

The company is calling its new program Tested To Be Trusted. CVS's senior vice president, Coleman, says it aims to give customers who are increasingly trying to foster their own health added confidence that "what's in the bottle is on the label."

"Consumers are moving to this proactive health and wellness stance," he says, "and we don't want to follow. We want to help lead in that, and help our customers."