FDA Unique Ingredient Identifiers (UNIIs)
FDA’s Global Substance Registration System enables efficient and accurate exchange of information on substances through their Unique Ingredient Identifiers (UNIIs) which can be generated at any time in the regulatory life cycle.
UNIIs are generated based on scientific identity characteristics using ISO 11238 data elements. UNII availability does not imply any regulatory review or approval. Synonyms and mappings are based on the best public information available at the time of publication. Please report any problems/errors associated with this data to FDA-SRS@fda.hhs.gov.
Monthly-ish - kind of every 2-3 months sometimes