| Abbreviation | Definition |
|---|---|
| IMTS | Industry Meeting Tracking System |
| INA | Investigational New Animal drug number |
| INAD | Investigational New Animal Drug |
| INADA | Investigational New Animal Drug Application |
| INCI | International Nomenclature of Cosmetic Ingredients |
| IND | Investigational New Drug |
| INDA | Investigational New Drug Application |
| INDC | Investigational New Drug Committee |
| INDE | Investigational New Drug Exemption |
| INFARMED | Instituto Nactional da FARMaciae e do MEDicamento (Portugal) |
| INN | International Non-proprietary Name |
| INNS | International Neural Network Society |
| INRO | Intramural NIAID Research Opportunities (National Institute of Allergy and Infectious Diseases) |
| INS | Incident of National Significance |
| INVSAMPLE | INVestigational Sample |
| IO | Immediate Office |
| IOB | International Operations Branch (ORA) |
| IOM | Investigation Operations Manual |
| IOTF | Interagency Oncology Task Force |
| IP | Information Panel |