Clinical trials

How many finished clinical trials post their results?

21.4% of the clinical trials completed in 2024 had posted results on ClinicalTrials.gov by September 2026, down from 35.6% of those completed in 2008, when a U.S. law began requiring results for many trials. That law covers mainly U.S. trials of drugs and devices past Phase 1, so many trials, including most outside the U.S., don't have to post here; some publish results in journals instead. Results are due a year after a trial ends, so the chart stops two years back, and a year's share can still rise.

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Source and date

Data as of
Published

The data

Year the trial was completed % of completed trials with results posted
2008 35.6
2009 35.6
2010 34.7
2011 32.4
2012 32.8
2013 32.1
2014 31.9
2015 29.5
2016 29.2
2017 27.7
2018 26.4
2019 25.6
2020 25.2
2021 24.2
2022 24.1
2023 22.5
2024 21.4