NSF/ANSI 173 Dietary Supplements
Issued by NSF International / ANSI
StandardAudit Scope
American National Standard establishing requirements for testing the content of dietary supplement products: active ingredient label-claim verification, identification of undeclared ingredients, and contaminant testing (heavy metals, microbiological, pesticides).
What It Proves
Product tested per NSF/ANSI 173 protocol confirms label-claim accuracy for active ingredients and that contaminant levels fall below standard thresholds. Distinct from facility GMP certification.
What It Does Not Prove
Does NOT certify the FACILITY (NSF/ANSI 455-2 / NSF GMP is the facility-level standard). Does NOT confirm long-term safety, drug-interaction profile, or efficacy. Does NOT certify the product as a drug — FDA regulates that pathway separately. A facility may be NSF/ANSI 455-2 certified without ALL its products being NSF/ANSI 173 tested.
How Vendors Report It
You may see this listed as:
Evaluating Manufacturer Credentials?
Our directory shows certification status, verification details, and assessment rationale for every listed vendor.