FDA Substance Registration System to Move from NLM to FDA

[Update: On December 17, 2021, this article was updated with the link to the new FDA-hosted site.]

In December 2021, the FDA Substance Registration System (FDA SRS) will move from the National Library of Medicine (NLM) to the U.S. Food and Drug Administration. FDA SRS is a resource for searching and downloading Unique Ingredient Identifiers (UNIIs) representing over 120,000 substances in FDA-regulated products. The new FDA-hosted site is accessible now, and links referencing the NLM site will begin redirecting to the new site soon. Please update your links and bookmarks with the new SRS link: https://precision.fda.gov/uniisearch.

If you have any questions, please contact the NLM Support Center.