Health products policy and standards
Our team provides authoritative guidance and standards on quality, safety and efficacy of health products and supports countries to formulate evidence-based policies and ensure good practice throughout the value chain.
INN stems
To select an appropriate stem, please read carefully
5 November 2007
Guidance on the establishment of new INN stems - 20070611
Guidance for INN applicants with regard to the establishment of new INN stems
All about existing stems and pre-stems can be downloaded here:
5 February 2026
INN Stem Book Addendum 202602-2024
The document "Use of stems in the selection of International Nonproprietary Names (INN) for pharmaceutical substances" is intended primarily for persons...
8 February 2026
Pre-stems: Suffixes used in the selection of INN - February 2026
The step before the adoption of an INN stem by the INN Expert Group is to publish them as a pre-stem in order to collect possible issues.