international nonproprietary name

An international nonproprietary name, or INN, is the single official global name for a drug's active ingredient. Think of it as the chemical's universal first name, the one that stays the same no matter who makes it or what they call their product on the shelf. Wherever you are in the world, the INN points to exactly the same substance.

INNs are assigned by the World Health Organization to make medicines unambiguous across countries and languages. They are deliberately not owned by any company, so any manufacturer of that substance uses the same name. INNs also follow patterns: shared word stems signal shared chemistry or action. Drugs ending in '-pril' are ACE inhibitors, those ending in '-olol' are beta-blockers, and many monoclonal antibodies end in '-mab'.

The INN is the backbone of the generic naming system. National bodies sometimes issue their own adopted names that usually match the INN closely. The INN sits in contrast to the brand name, which is a company's marketing trademark; one substance has one INN but may carry many different brand names in different markets, which is why knowing the INN prevents dangerous confusion between products.