Clinical Trial Statistics 2026

Zooming out: the entire registry

Everything above comes from ClinicalMetric's own daily feed. This part doesn't. On 28 September 2026 we counted all 604,566 studies on ClinicalTrials.gov, every status, every year, so you can see where the recruiting slice sits inside the whole thing.

Only about one study in nine is open.

65,044 are recruiting right now, which is 10.8% of the registry. Add the 29,938 that say they'll open soon and the 5,263 enrolling by invitation, and you're still at about one in six.

"Unknown status" is the second-biggest group, and it's not a small footnote.

ClinicalTrials.gov puts a study here when its record still says it is ongoing, its expected completion date has passed, and nobody has verified the record in more than two years. 96,838 studies, 16.0% of everything registered, have gone quiet like this. If you find an interesting study with this label, contact the site before you get your hopes up.

Stopped studies add up.

Terminated (34,380), withdrawn (16,812) and suspended (1,777) together come to 52,969 studies. We looked at why they stop in our analysis of terminated and withdrawn trials. Short version: running out of participants beats every scientific reason combined.

Of the recruiting studies, 47,506 are interventional (they test something) and 17,538 are observational (they watch and measure). 12,806 accept healthy volunteers. Source: ClinicalTrials.gov API v2, 28 September 2026. These figures are a fixed snapshot and won't move with the daily feed above.