US clinical trial statistics

A citable snapshot of US clinical-trial activity, compiled from the public ClinicalTrials.gov registry maintained by the NIH National Library of Medicine. Every figure below is drawn directly from the registry and refreshed from the public source.

60,823
US clinical trials indexed
22,403
recruiting now (37% of total)
30,015
distinct conditions studied
8,714
sponsoring organizations
52
states & territories with sites

Trials by phase

Of the 60,823 indexed trials, the largest reported phase is Phase 2; many trials report no applicable phase (observational or expanded-access studies). According to ClinicalTrials.gov, phase is self-reported by each study's sponsor.

Not Applicable21335Phase 210294Phase 19771Phase 35207Phase 42744Early Phase 11076
US clinical trials by reported phase — ClinicalTrials.gov registry.

Most-studied conditions

  1. 1. Breast Cancer 1,251
  2. 2. Healthy 1,096
  3. 3. Obesity 1,057
  4. 4. Prostate Cancer 747
  5. 5. Depression 687
Full rankings →

Most-active sponsors

  1. 1. M.D. Anderson Cancer Center 1,252
  2. 2. National Cancer Institute (NCI) 1,210
  3. 3. Mayo Clinic 1,066
  4. 4. Memorial Sloan Kettering Cancer Center 955
  5. 5. Massachusetts General Hospital 746
All sponsors →

Source: ClinicalTrials.gov (NIH/NLM) ClinicalTrials.gov AACT registry · 2026 All counts derived directly from the public ClinicalTrials.gov registry. Phase and recruitment status are sponsor-reported.

Read our methodology — how these figures are sourced, computed, and refreshed.

Verify with NIH →