The international nonproprietary name (INN; German translation: internationaler Freiname) is the unique name recommended by the World Health Organization (WHO) for an active pharmaceutical ingredient that can be used to clearly identify it worldwide. The INN is the standardized and latinized name of an active pharmaceutical ingredient, which does not generally contain any brand names or trademarks.

The main purpose of the INN is to facilitate the exchange of information on drugs between medical and pharmaceutical professionals, researchers and regulatory authorities and to avoid confusion that can be caused by different trade and brand names for the same active pharmaceutical ingredient (German: Wirkstoff). This is particularly important in medical practice and research, where accuracy and clarity are crucial when it comes to identifying drugs.

Examples of INNs are:

• Acetylsalicylic acid, a cyclooxygenase inhibitor
• Diazepam, a benzodiazepine
• Amoxicillin, a penicillin antibiotic
• Atenolol, a beta-blocker

The INN was proposed by the World Health Organization (WHO; translation into German: Weltgesundheitsorganisation) and has been approved by national nomenclature committees. Every drug has only one INN, regardless of how many different brand names there may be on the market.

Clear terminology is also crucial for pharmaceutical interpreters and GMP translators, for example when accompanying GMP inspections or preparing pharmaceutical translations.