The move comes after the death last month of Baltimore Orioles pitcher Steve Bechler during spring training, after he had taken ephedra, an herb commonly used for weight loss and body building.
Even with the new rules, there still will be no guarantee that the pills or powders work or even are safe to swallow.
But the Food and Drug Administration's factory rules aim to ensure that the ingredients and dosages promised on a supplement's bottle really are contained inside, without any dangerous contaminants.
They're a cross between the manufacturing standards required for foods and for over-the-counter drugs like aspirin. Until now, only a small portion of the supplement industry has followed voluntary quality standards.
Too often, this is "a buyer-beware market," said FDA Commissioner Mark McClellan. "Consumers should have access to dietary supplements that are accurately labeled and free from contaminants."
The FDA estimates that are at least 1,000 makers of dietary supplements sell in the United States, a $19 billion industry that is exempt from most safety oversight. Under a 1994 law, supplements can be sold without first proving they're safe or truly deliver the benefits they advertise; there isn't even any way to ensure a bottle contains the promised amount of pure ingredients.
Over and over in recent years, scientists and consumer groups have tested bottles of supplements and found fraud. The FDA cited a recall of a line of supplements discovered contaminated with brain-toxic lead. In another case, a maker of folic acid — a nutrient taken by pregnant women to reduce birth defects — recalled the pills after scientists discovered they contained only a third of the amount listed on the label, meaning women didn't get the protective amount necessary.
The new manufacturing standards aim to prevent such problems by, among other things, requiring certain quality-control steps that include company testing of ingredients and finished products for contamination and the promised dose.
The proposed rules will be open for public comment for three months. McClellan said he expected to issue final regulations next year. Bigger manufacturers will have to comply first, with small companies given up to three years to implement the rules.
FDA inspections, focusing most on "the potential bad actors," will ensure the rules are followed, McClellan said. But a segment of the supplement industry has long called for the manufacturing standards, and McClellan said he expected more reputable firms would implement the proposed rules right away.
"The responsible manufacturers are happy to comply," said John Hathcock of the Council for Responsible Nutrition, which represents 80 companies that follow voluntary quality standards. Other manufacturers "cloud our whole industry, and we're glad to see federal action to force them to ... get in line or get out of business."