unii

is a Data Source.

FDA's Global Substance Registration System (GSRS) is a comprehensive database that provides Unique Ingredient Identifiers (UNIIs) for substances in FDA-regulated products. UNIIs uniquely define substances based on scientific identity characteristics using ISO 11238 data elements, enabling efficient and accurate exchange of substance information across regulatory domains.

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Domains

clinical, drug discovery, pharmacology, public health

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Homepage

unii

Repository

ginas.ncats.nih.gov

External IDs
  • Infores: infores:unii

Product Summary

Products

From this Resource
ID Name URL Category Format Description
unii.search UNII Search Service uniisearch Graphical Interface http Web-based search interface for findin...
unii.list ⚠ UNII List Download UNIIs.zip Product csv Downloadable list of all UNIIs with b...
unii.data ⚠ UNII Data Download UNII_Data.zip Product mixed Comprehensive UNII data with detailed...
unii.legacy ⚠ Legacy UNIIs Legacy_UNIIs.txt Product txt Legacy UNII identifiers for historica...
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Details

FDA Global Substance Registration System (UNII)

The FDA’s Global Substance Registration System (GSRS) is a comprehensive, authoritative database that generates Unique Ingredient Identifiers (UNIIs) for substances in FDA-regulated products. Developed through collaboration between the FDA’s Informatics team, NIH’s National Center for Advancing Translational Sciences (NCATS), and the European Medicines Agency (EMA), GSRS addresses the critical need for accurate substance identification across global regulatory domains.

Overview

UNIIs are generated based on scientific identity characteristics using ISO 11238 data elements, providing standardized identifiers that transcend the variability of substance names across different regulatory domains, countries, and regions. The system classifies substances as chemical, protein, nucleic acid, polymer, structurally diverse, or mixture as detailed in ISO 11238 and ISO DTS 19844 standards.

Key Features

  • Comprehensive Coverage: UNIIs can be generated for any substance at any time in the regulatory life cycle, from atoms to organisms
  • Global Standardization: Enables efficient and accurate exchange of substance information across regulatory domains
  • Scientific Classification: Substances are defined by standardized, scientific descriptions rather than variable names
  • Regulatory Integration: Used in electronic listing systems like DailyMed and throughout product life cycles including clinical trials, marketing, and post-market surveillance

Products and Access

The GSRS provides multiple ways to access UNII data:

  1. UNII Search Service: Interactive web interface for searching substances by UNII, name, or other identifiers
  2. Downloadable Data: Comprehensive datasets including UNII lists and detailed substance data
  3. Public GSRS Interface: Full access to the Global Substance Registration System hosted by NCATS
  4. PrecisionFDA Integration: Collaborative tools for filtering, exporting, and creating GSRS records

Applications

UNII identifiers are essential for:

  • Drug labeling and electronic submissions
  • Clinical trial identification
  • Product safety monitoring
  • Global supply chain tracking
  • Regulatory compliance across FDA-regulated products (food, drugs, tobacco, cosmetics)

Data Quality and Updates

The system is regularly updated, with the most recent data refresh on August 18, 2025. UNIIs are generated based on the best available public information, and synonyms and mappings are continuously refined. The FDA encourages reporting of data issues to maintain accuracy and completeness.

Is this information incorrect or incomplete? Request an update.

Created: July 17, 2025 | Last modified: June 12, 2026