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GUIDANCE DOCUMENT

Clinical Pharmacology Considerations for Human Radiolabeled Mass Balance Studies September 2024

Download the Final Guidance Document Read the Federal Register Notice
Final
Docket Number:
FDA-2022-D-0113
Issued by:
Guidance Issuing Office
Center for Drug Evaluation and Research

This guidance describes the FDA’s recommendations regarding clinical pharmacology considerations for conducting human radiolabeled mass balance studies of investigational drugs, including: (1) deciding whether and when to conduct the study, (2) designing the study, and (3) reporting results. This guidance does not cover animal mass balance studies, safety testing of drug metabolites, or recommendations for selecting the radioactive dose.

Additional Guidance Resources: 

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