Medical Information Only. Consult your healthcare provider before enrolling in any clinical trial.
Iowa: below-average open trial sites
508 of 1,544 in-state trials are recruiting (33%); below the 37% national average by 4 percentage points.
According to ClinicalTrials.gov-derived indexes, Iowa sits in the lower half of US states by in-state trial count (#33 of 52 states by registered in-state trial count).
Iowa: 1,544 US clinical trials with in-state sites, 508 recruiting.
Iowa has 1,544 registered US clinical trials with a study site in-state, 508 of them currently recruiting (below the 37% national average by 4 percentage points). 360 of these trials are in Phase 3 (late-stage) and 367 in Phase 2. The most frequently studied condition in Iowa is Breast Cancer, with 35 linked trials.
Lower-half Iowa archive
Iowa's in-state trials target 5,137 patients on average (p73 by trial size among 52 states with enrollment data), larger, multi-site studies than most states. Treat this page as a compact local index (mid-volume · mid-open), then jump to recruiting trials or methodology rather than expecting hub-scale coverage.
Below-average open enrollment
Iowa still shows 508 recruiting of 1,544 in-state trials (33% open), but below the 37% national average by 4 percentage points, so archived statuses weigh heavier than the national baseline.
- 33%
- open (below national share)
- 508
- still recruiting despite cool share
- 367
- Phase 2 rows in this footprint
- 35
- top: Breast Cancer
Recruiting share is below the 37% national average by 4 percentage points. Counts include every study with at least one recorded site in the state. Registry reference only, not medical advice.
Iowa vs all states by indexed in-state trial count
Where this state's ClinicalTrials.gov site count sits among every state with at least one listed trial (coverage density, not care quality)
1,544 Top 63% more indexed trials than 37% of 52 states
States, banded by indexed in-state trial count
Each bar is a band; taller bars hold more states. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.
Source ClinicalTrials.gov · 2026-08-08
Key findings
What ClinicalTrials.gov does not surface for Iowa on its own pages , computed from the registry mirror as of 2026-08-08. Each line carries its own denominator so it can be quoted as it stands.
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Iowa open-enrollment share sits below the national baseline.
508 of 1,544 in-state trials (32.9%) are recruiting, against 37% nationally (-4.1 percentage points). Counts include every study with at least one recorded site in the state.
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Iowa City dominates Iowa's trial geography.
Iowa City lists 1,132 of 1,544 in-state trials (73.3%) across 253 named facilities. Cities need five or more listed trials to appear here; locations are as filed by sponsors.
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Breast Cancer is the most-studied condition in Iowa.
35 of 1,544 in-state trials (2.3%) list Breast Cancer. That is a local concentration figure, not a national disease ranking.
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Iowa sponsorship is fragmented across many organizations.
University of Iowa appears on 72 of 1,544 in-state trials (4.7%). Sponsor identity is as filed on ClinicalTrials.gov.
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658 Iowa trials carry a completed status.
658 of 1,544 (42.6%) are completed. The open share above is the remainder that still lists recruiting.
By Status
| Status | Trial count |
|---|---|
| Completed | 658 |
| Recruiting | 508 |
| Active | 378 |
By Phase
| Phase | Trial count |
|---|---|
| Phase 2 | 367 |
| Phase 3 | 360 |
| NA | 322 |
| Phase 1 | 181 |
| Phase 4 | 63 |
| Early Phase 1 | 22 |
Top Conditions
Top Sponsors
Where trials run in Iowa
Iowa City carries 1,132 of Iowa's 1,544 indexed trials (73%) across 253 named sites, ahead of Des Moines at 152. 8 cities clear five listed trials, together naming 498 distinct sites.
| City | Trials | Listed sites |
|---|---|---|
| Iowa City | 1,132 | 253 |
| Des Moines | 152 | 83 |
| West Des Moines | 95 | 47 |
| Sioux City | 72 | 36 |
| Cedar Rapids | 50 | 22 |
| Ames | 39 | 19 |
| Davenport | 36 | 24 |
| Waukee | 22 | 14 |
Distinct trials and named sites per city, as filed with ClinicalTrials.gov; cities under five trials omitted. Vintage 2026-08-08.
Trial size large
Iowa's in-state trials target 5,137 patients on average (p73 by trial size among 52 states with enrollment data), larger, multi-site studies than most states.
Iowa: in-state trial volume sits mid-pack
Geography is concentrated: Iowa City alone accounts for 73% of Iowa's indexed trials (1,132 of 1,544), with Des Moines a distant second at 152.
Phase mix: 360 Phase 3 vs 367 Phase 2 (balanced across stages).
Top condition: Breast Cancer (35 trials); top sponsor University of Iowa (72).
mid-volume · mid-open figures (1,544 trials · 33% open) describe registry geography under the trial size large read, not clinic capacity or protocol fit. Confirm status on ClinicalTrials.gov before acting.
States near Iowa on in-state trial volume
Cross-state peers under the trial size large read (mid-volume · mid-open), not the same-state browse list.
Similar mid-volume peers (± open share)
- South Carolina · 1,706 trials · 35% recruiting
- Utah · 1,734 trials · 38% recruiting
- Wisconsin · 1,760 trials · 37% recruiting
- Nebraska · 1,301 trials · 29% recruiting
- Louisiana · 1,936 trials · 28% recruiting
Similar mid-open peers (± trial volume)
- New Hampshire · 33% recruiting · 471 trials
- California · 33% recruiting · 16,646 trials
- North Carolina · 33% recruiting · 5,625 trials
- Florida · 33% recruiting · 10,986 trials
- Washington · 33% recruiting · 2,795 trials