If you purchase a bag of peanuts but get pretzels instead, it is obvious. But with supplements, you really have no way of telling whether you did, in fact, get just what you paid for -- until now. There are three testing programs underway putting supplements under close scrutiny for you, the consumer.

One-quarter of the first 571 supplements tested by one program, ConsumerLab.com, did not contain the amount of the product stated on the label, were contaminated, or did not dissolve properly. To be sure, these programs are not yet testing whether supplements actually work. But to make sure you get your money's worth, these programs are a huge step in the right direction.

United States Pharmacopeia (USP), a nonprofit organization authorized by Congress to set standards for the drug industry, has launched a Dietary Supplement Verification Program. Manufacturers pay USP to get products tested. They can use a USP mark on a supplement label if it passes tests for label accuracy, lack of contamination and good manufacturing practices. After approval, companies are subject to random product testing and audits. Pharmavite, makers of Natur Made, is the first supplement company to submit their products for the USP mark.

NSF International, also a nonprofit organizations, offers the Dietary Supplement Certification Program. Manufacturers pay a fee to be tested by NSF. They can use the NSF mark on supplement labels if products pass the same tests as the USP's. Products continue to be monitored. At the time of release, nearly 60 dietary supplements from two companies (Nutrilite and Perrigo) can use the NS mark on labels.

ConsumerLab.com, a private company, periodically selects about 20 different brands of supplements from a single category to test for label accuracy, lack of contamination and dissolution. For a 17.95-dollar yearly subscription to ConsumerLab.com's Web site, you can see the names of more than 400 supplements that have passed their tests. Sadly, few manufacturers have opted to carry ConsumerLab.com's Seal of Approved Quality of their labels, but many are making sure to get their products tested. To carry the seal, manufacturers must pass ConsumerLab.com's test, have their product reanalyzed yearly and be willing to pull the product from stores if there are any problems.

Helpful Online Resources:

National Center for Complementary and Alternative Medicine -- Herbal Supplements:  Consider Safety, Too

FDA/CFSAN Dietary Supplement Health and Education Act of 1994