KANSAS CITY, Mo. -- The New York Attorney General recently accused some of the country's major retailers of selling some dietary supplements that don't contain the main ingredient listed on the label. So how do you know which supplements to trust? Look for a seal of approval.
Unlike drugs, no dietary supplement is FDA-approved.
"There are many, many problems with quality of the supplements that are out there," said Dr. Cydney McQueen, a clinical associate professor at the UMKC School of Pharmacy.
Dr. McQueen says your best bet for getting a good quality product is to look for the USP seal of approval. USP stands for United States Pharmacopeia.
"Things have to be tested when they first come into the factory, during the manufacturing process and then the end result. Not necessarily every single batch but they're going to be monitoring very, very frequently," she said.
Nature Made products have the USP seal. So do Kirkland products sold by Costco. Dr. McQueen says while the seal is on some vitamins and minerals, it's only on one herbal product although she expects that number will increase. She adds that out of a thousand herbal supplements, USP has developed quality standards for only 29 of them.
Dr. McQueen says another seal to look for is GMP which stands for good manufacturing practices. It's a testing program of the Natural Products Association.
She cautions that a lot of companies come up with their own seals. She showed us one that says "Purity Quality Guaranteed."
"They have statements on there that say they're certified in some way or they're clinically-proven which doesn't mean anything about the quality," said Dr. McQueen.
So read closely to make sure you're getting a real seal of approval.
Dr. McQueen says you can also CLICK HERE to find supplements tested by Consumer Lab. Consumer Lab tests products taken off of store shelves and then publishes the results.