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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Key facts

Measure: % of completed trials with results posted. Written from the data below.

  • The latest figure, for 2024, is 21.5%.
  • That is down 14.1 percentage points from 35.6% in 2008.
  • The highest was 35.6%, first reached in 2008.
  • It is the lowest in the data, which go back to 2008.

Source and date

Source
ClinicalTrials.gov (U.S. National Library of Medicine), counted with its API v2
License
Public domain (U.S. government work); source National Library of Medicine
Data as of
Published

Citation

Chartly. “How many finished clinical trials post their results?” Chart. Data: ClinicalTrials.gov (U.S. National Library of Medicine), counted with its API v2, https://clinicaltrials.gov/data-api/api (data as of October 15, 2026). https://chart.ly/charts/clinical-trials-reporting-results (accessed October 15, 2026).

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The data

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The file has the numbers in this table, with the source, license and date. Please credit the source and Chartly.

Year the trial was completed % of completed trials with results posted
2008 35.6
2009 35.6
2010 34.6
2011 32.4
2012 32.9
2013 32.1
2014 31.9
2015 29.5
2016 29.2
2017 27.7
2018 26.4
2019 25.5
2020 25.2
2021 24.3
2022 24.2
2023 22.5
2024 21.5

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