Research & Regulation
Phase 3 Clinical Trial
Also called: Phase III, phase three
Definition
A later-stage clinical trial designed to provide substantial evidence about efficacy and safety in the intended population and use context.
What Phase 3 Clinical Trial means
Phase 3 programs are typically larger and more confirmatory than earlier phases and may support a regulatory application when results and the broader evidence package are sufficient.
Why the distinction matters
Even positive Phase 3 results do not themselves equal FDA approval; regulatory review is a separate step.
Common confusion
“In Phase 3” and “FDA-approved” are not interchangeable statuses.
See this concept in context
Open the BACToBasics tools and reference pages where this term is used.
Keep learning
Related glossary terms
Research & Regulation
Phase 2 Clinical Trial
A stage of human clinical development that commonly explores efficacy signals, dose selection, and continued safety assessment.
Research & Regulation
FDA-Approved
A status indicating that the FDA has approved a specific drug product for one or more labeled uses after reviewing the required evidence and manufacturing information.
Research & Regulation
Investigational
A compound, product, or use that is being studied and has not received approval for general marketing for that use.
Research & Regulation
Randomized Controlled Trial (RCT)
A study in which participants are assigned by a random process to different intervention or control groups.
Published September 6, 2026. BACToBasics glossary pages are educational definitions only and do not provide medical, dosing, preparation, treatment, or product-selection advice.