Private Supplement Watchdog Groups?>

Private Supplement Watchdog Groups

by Andrea Klausner, MS, RD  

Some supplements carry “seals of approval” from independent certification programs, which claim to keep tabs on the industry. These include:

  • The best-known certification program comes from this private company, which has analyzed thousands of products in most popular supplement categories. randomly buys products from stores, from catalogues, over the internet, or through multilevel marketing companies, and then sends them to independent labs for testing. The labs test for identity of ingredients, strength, contamination, and ability to disintegrate. Results are posted in the product reviews on If a product passes muster, it can then, for a licensing fee, display the “Approved Product Quality” seal on its label and in advertising, subject to periodic retesting. Manufacturers may also pay to have their products tested under’s Voluntary Certification Program.
  • The U.S. Pharmacopeial Convention (USP). This nonprofit organization, which sets standards for drug manufacturers, also certifies supplements that pass testing under its Dietary Supplement Verification Program. For a fee, manufacturers can have products analyzed for accuracy of labeling, purity, and speed of disintegration. USP, unlike, tests more than the finished product; it also makes sure the supplement is made according to good manufacturing practices. If it passes testing (and random retesting) and an on-site manufacturing plant audit, the product may display the “USP Verified” seal.
  • NSF International. This nonprofit organization, best known for certifying bottled water and water filters, also evaluates supplements under its voluntary certification and testing program. Products made under good manufacturing practices, with accurate ingredient labels and no contaminants, may display the NSF seal. Testing is done, for varying fees, in NSF’s own accredited labs.

Certification programs help ensure that a supplement contains what it claims, without impurities. But they have limitations, such as:

  • There is debate about the testing methods used, which can vary from lab to lab. If a product passes in one lab, it may not pass in another. Companies may test samples from only a few lots, and different lots can vary widely in quality and purity.
  • Products that fail are not always identified. If a product doesn’t meet testing standards, nothing on its label will warn you.
  • Products without seals are not necessarily inferior. They simply may not have been tested.
  • The seals don’t address the big questions: Is the product safe? And does it work? While the seals indicate that the products passed certain tests for quality, they are not proof of safety or efficacy.

This article first appeared in the UC Berkeley Wellness Letter.