> ## Content Index
> Fetch the complete content index at: https://www.fdaweb.com/llms.txt
> Use this file to discover other available public pages before exploring further.

# Guide on Radiolabeled Mass Balance Studies
- URL: https://www.fdaweb.com/guide-on-radiolabeled-mass-balance-studies/
- Published: 2022-05-05T12:00:00.000Z
- Updated: 2026-09-14T17:43:24.000Z
- Author: David McFarland
- Tags: FDA Policy/General, #legacy-id-D5151754

*Federal Register* notice: FDA has made available a draft guidance entitled “Clinical Pharmacology Considerations for Human Radiolabeled Mass Balance Studies.” The document describes agency recommendations on deciding whether and when to conduct such studies, study designs, and reporting results. To view the notice, click [here](https://www.govinfo.gov/content/pkg/FR-2022-05-05/pdf/2022-09608.pdf?ref=fdaweb.com).