Most IRB reviews run 1–8 weeks, depending on review level, meeting cycles, and submission quality.
The clock on ethics approval depends on three levers: the review path your project qualifies for (exempt, expedited, or full board), the meeting rhythm of the committee, and how clean your packet is when you hit “submit.” This guide lays out plain-English timelines, what drives delays, and simple ways to shave days off the process.
How Long An IRB Review Usually Takes By Type
Time ranges below reflect common patterns across major research universities and health systems. Real numbers vary by institution and season, so use these as planning anchors, not guarantees.
| Review Path | Typical Timeline | What Usually Drives The Pace |
|---|---|---|
| Exempt (minimal risk, fits a regulatory category) | 2–15 business days; some sites post ~3–4 weeks in busy periods | Clear fit with exemption, clean consent/notice language, data de-identification |
| Expedited (minimal risk; reviewer(s) outside a full meeting) | 2–6 weeks, often near 2–3 weeks when files are complete | Category match, privacy safeguards, ancillary sign-offs (e.g., data use, HIPAA) |
| Full Board (greater than minimal risk or does not fit expedited) | 3–8 weeks from submission to approval, tied to meeting dates | Agenda load, pre-review rounds, responses to requested changes |
Why the spread? Some IRBs publish rolling data that land near 2–3 weeks for minimal-risk routes and ~1 month for convened review. Others quote longer windows during heavy submission seasons or holidays. A spotless packet shortens every path.
What Each Review Path Means In Practice
Exempt Certification
This route covers specific categories of minimal-risk work set in federal rules. The office confirms that your project fits an exemption and that basic privacy and consent notices meet policy. No convened meeting is required. Many offices turn these around in days when documents are tight and instruments are attached.
Expedited Review
One or more experienced reviewers handle the file outside a full meeting. The study still needs a solid consent plan, privacy safeguards, and a crisp description of activities and data flow. This path is common for survey work, interviews, chart review, and some device or software interactions that meet minimal-risk criteria. See the federal list of expedited categories for the exact scope.
Full Board Review
Projects that go beyond minimal risk, or do not fit an expedited category, land on a convened agenda. Timing tracks to the next available meeting, any pre-review edits, and the speed of your responses. Many boards meet monthly; some run twice per month. If you miss a deadline, your file waits for the following agenda.
What Drives Delays (And How To Avoid Them)
1) Missing Or Mismatched Documents
Common gaps include unstamped consent forms, instruments that do not match the protocol, or a data plan that conflicts with what the consent promises. Build a one-page checklist and confirm that filenames match section titles in the application. Reviewers finish faster when every claim in the protocol points to a clear attachment.
2) Ambiguity In Data Handling
Time slows when the application says “de-identified” but the dataset includes dates, free text, or unique codes that could re-link. Spell out your identifiers, coding scheme, storage location, and retention period. If you are using limited datasets or a data use agreement, include the draft.
3) Consent Language That Conflicts With Activities
If you promise “no follow-up,” then add a later survey, the office will send it back. Keep consent plain and aligned with procedures, including compensation, risks, and withdrawal steps. Translate consent into all study languages before submission when you can. That single step can save weeks.
4) Ancillary Reviews
Some projects need sign-off from privacy, radiation safety, biosafety, or device/drug regulation teams. Line these up early. If your work includes a regulated product, skim the eCFR section on expedited procedures to see what qualifies for minimal-risk handling.
5) Calendar Logistics
Full board routes live and die by meeting cycles and submission cutoffs. Grab the current calendar and aim one cycle ahead. If your site uses pre-review, submit several days before the posted deadline so staff can flag fixable issues without bumping you.
Clean-Submission Blueprint
Use this quick build order. It mirrors what reviewers scan first and cuts down questions.
Protocol Core
- Plain title that matches the consent heading and survey headers.
- Short aims written in everyday language.
- Step-by-step procedures with who, where, and duration.
- Inclusion and exclusion in bullet form; list any vulnerable groups.
- Data plan: fields collected, identifiers, coding, storage, retention, sharing.
- Risk list with direct mitigations next to each item.
- Compensation, costs, and contact lines.
Consent And Recruitment
- Readable consent (grade-level target near 8–9 works for most adult studies).
- Contact info that routes to a monitored inbox or phone line.
- Recruitment copy that matches consent promises and avoids pressure.
- Translations ready at submission when the study enrolls multilingual groups.
Data And Privacy
- Encryption at rest and in transit for sensitive fields.
- Access list with named roles and least-privilege design.
- De-identification method for any shared dataset or publication archive.
- Plan for withdrawals and data destruction, if requested by participants.
How To Read Posted Timelines
Many IRBs share quarterly or annual turnaround stats. These numbers often report “calendar days with the IRB,” which excludes time your file sits with the study team. A fast office can still show a long median if investigators take weeks to reply to requested edits. When you see a number labeled “75th percentile,” that means three-quarters of submissions finished within that number of days; complex files tend to sit in the remaining quartile.
Step-By-Step Timeline From Draft To Approval
The schedule below covers the full arc for a new protocol, from first draft to green light. Adjust the windows to your local calendar and staffing.
| Stage | Typical Window | Speed Tips |
|---|---|---|
| Pre-review With Lab Or Mentor | 2–5 days | Run a local checklist; align consent, protocol, and instruments |
| Ancillary Clearances (data, safety, conflicts) | 3–10 days | Start in parallel; attach draft DUAs and any safety plans |
| IRB Intake Check | 1–3 days | Use consistent filenames; respond same-day to intake questions |
| Exempt/Expedited Review | 2–15 business days | Point to the exact exemption or expedited category in the cover memo |
| Full Board Agenda + Meeting | 2–4 weeks to meeting; 1–2 weeks post-meeting edits | Submit before the cutoff; prepare short, direct replies to stipulations |
| Final Letter Issued | Same day to 1 week after all changes are accepted | Upload clean, stamped forms; confirm version dates match |
Real-World Ranges Posted By Institutions
Across recent public dashboards and policy pages, you will see minimal-risk routes landing near two weeks when files are complete. Some sites post faster responses for simple exempt determinations in light workloads. Full meetings tend to place median times near one month, with longer tails when agendas are packed or holidays intervene. These figures ebb and flow by term and staffing.
How To Cut Days Off Your Timeline
Submit A Self-Contained Packet
Upload every instrument, script, message, and flyer. If a link points to a survey, include a PDF export with branching logic. If you plan phone or video contact, add a short script and privacy note about recording.
Write For Readers Outside Your Field
Board members span many backgrounds. Short, direct prose speeds comprehension. Swap jargon for everyday words. Keep acronyms to a minimum and define them on first use.
Be Specific About Data
List exact fields you will collect, how you will store them, and who can see them. If you will share a dataset, flag whether it is de-identified or limited, and include the vetting steps you will use before any release.
Map Risks To Mitigations
Place each risk next to the control you will use. If interviews could surface distress, name the pause/stop rules and referral steps. If online forms carry a risk of breach, note encryption, access controls, and retention limits.
Hit The Right Category
Pick the path that fits your design and risk. The expedited list and related guidance spell out what qualifies. If your work does not fit, send it to a convened meeting without trying to force a lower route. That choice saves a reroute and a month of waiting.
What Changes After Approval
Minimal-risk routes may carry no annual expiration at some sites, yet the study still stays under oversight. You still submit amendments, report events, and close out when complete. Full board or device/drug-involved work can require continuing review or extra reports. Factor that into your project plan so follow-on work does not stall later.
Seasonal And Project-Specific Factors
Academic Calendar
Submissions spike near grant deadlines and in the weeks before breaks. Aim for quieter windows when you can. If your site posts meeting dates, plan backward from the agenda that best fits your start date.
Population And Setting
Work with children, patients, or sensitive topics can lengthen review due to added safeguards. Multi-site projects that need single-IRB coordination also add steps. Budget extra time for reliance agreements and local context reviews.
Technology And Apps
Studies using apps, wearables, or software often trigger added privacy and security checks. Add a short appendix that lists vendors, data flows, and storage regions. That single page prevents a volley of questions.
Mini Planner: Pick Your Path And Plan Your Start Date
Use this quick planner to peg a realistic launch date.
If You Fit An Exemption
- Build the packet in one week or less with complete instruments.
- Plan 1–2 weeks for office review, plus a few days for edits.
- Target your first participant within three weeks of submission.
If You Fit The Expedited Route
- Assemble all instruments and data plans before submission.
- Expect 2–3 weeks for review at many sites; longer in peak seasons.
- Hold time for one revision round; keep replies under 48 hours.
If You Need A Convened Meeting
- Pull the meeting calendar and submission cutoff today.
- Submit at least one cycle ahead; aim for pre-review one week early.
- Plan 1–2 weeks post-meeting for edits and the final letter.
Bottom-Line Planning Benchmarks
For most single-site studies with minimal risk, a clean packet submitted outside peak weeks lands approval in two to three weeks. Projects that need a convened agenda often reach the finish line in about a month, give or take the meeting cadence. Complex, multi-site, or higher-risk designs need a wider window.
Compliance Corner
If you need to confirm whether your design qualifies for expedited handling or must go to a full meeting, the federal pages are clear and concise. Start with the HHS list of expedited categories. For the legal text that governs when an IRB may use that path, see 45 CFR 46.110.
Quick FAQ-Style Notes Without The FAQs
“Can I Start Data Collection Before The Letter?”
No. Wait for the approval or exemption notice. Pre-tests that look like research can count as data collection.
“Do Editorial Edits Reset The Clock?”
Minor wording fixes rarely add time. Substantive changes (new arms, extra contacts, added biospecimens) can trigger deeper review.
“What If I Miss A Meeting Deadline?”
Your file rolls to the next agenda. Many boards publish cutoffs; set calendar alerts so you do not slip a cycle.
Takeaway
Plan two to three weeks for minimal-risk routes and four to eight weeks when you need a convened meeting. Build a complete packet, match the correct category, and respond fast to requests. That approach trims days off any path and gets your study moving on schedule.