An IRB, or Institutional Review Board, is a committee that reviews research studies involving people to make sure participants are protected from unnecessary harm. Before a researcher at a university, hospital, or other institution can enroll human volunteers in a study, the IRB must evaluate the plan and formally approve it. Every institution that conducts or supports research on people is required to have one, and the process is governed by federal regulations known as the Common Rule, last updated in 2018.
What an IRB Actually Does
An IRB’s core job is to look at a proposed study and answer one fundamental question: are the risks to participants reasonable given what the research might learn? To get there, the board evaluates several specific things. It checks that the study design minimizes risk by not exposing people to dangers that aren’t necessary for the research. It confirms that participant selection is fair, meaning the study isn’t recruiting from a group simply because they’re easy to access or unlikely to push back. It verifies that every volunteer will give informed consent, meaning they’ll be told what the study involves, what the risks are, and that they can quit at any time.
The board also looks at whether the research plan includes adequate protections for privacy and data confidentiality. For studies with higher stakes, such as drug trials, the IRB checks that there’s a plan for monitoring safety data as the study progresses, not just at the end.
The Ethical Principles Behind It
IRBs operate on three ethical principles laid out in the Belmont Report, a landmark 1979 document created after serious abuses in human research came to light, most notably the Tuskegee syphilis study in which Black men were left untreated for decades without their knowledge.
The first principle is respect for persons. People should be treated as capable of making their own decisions, and those who have limited ability to do so (such as young children or people with cognitive impairments) deserve extra protection. The second is beneficence: researchers are obligated to minimize harm and maximize potential benefits, not just avoid doing something obviously wrong. The third is justice, which asks who bears the burdens of research and who gets the benefits. An injustice occurs when one group is disproportionately recruited for risky studies while another group reaps the rewards.
Who Sits on an IRB
Federal regulations require at least five members with varied backgrounds. The board must include at least one person whose expertise is in a scientific field and at least one whose focus is nonscientific, such as ethics, law, or community advocacy. There must also be at least one member who has no affiliation with the institution, someone from outside who can offer an independent perspective. When a board regularly reviews research involving groups that are vulnerable to pressure or exploitation, such as children, prisoners, or economically disadvantaged people, membership should include someone with direct experience working with those populations.
Diversity matters here by design. Regulations specify that boards should reflect a range of racial, gender, and cultural backgrounds so the committee can recognize concerns that a more homogeneous group might miss.
Three Levels of Review
Not every study goes through the same process. The level of scrutiny depends on how much risk participants face.
- Exempt review applies to research that poses very little risk. Common examples include anonymous surveys, educational tests, and observation of public behavior. These studies still get reviewed, but through a streamlined process.
- Expedited review is for studies that carry no more than minimal risk and fit into a set of predefined categories. These include collecting small blood samples, recording interviews, gathering data through noninvasive methods, or studying already-collected biological specimens. One or two designated IRB members can review and approve these without convening the full board.
- Full board review is required for anything that doesn’t qualify for the first two categories. This means the entire committee meets, discusses the study, and votes. Drug trials, surgical interventions, and research involving more than minimal risk typically go through this process.
Extra Protections for Vulnerable Groups
Federal regulations add layers of protection for groups considered especially vulnerable. Separate regulatory subparts cover research involving pregnant women and fetuses, prisoners, and children. When a study targets any of these populations, the IRB must verify that additional safeguards are built into the research plan. For example, the board pays closer attention to whether consent is truly voluntary when participants are prisoners, since the power dynamics of incarceration can make it difficult to say no. For children, the board ensures a parent or guardian provides permission and that the child gives their own agreement (called assent) when they’re old enough to understand.
The regulations also flag people with impaired decision-making capacity and those who are economically or educationally disadvantaged as groups requiring extra care, even though they don’t have their own dedicated regulatory subparts.
Ongoing Oversight After Approval
An IRB’s job doesn’t end once a study is approved. Federal rules require continuing review at least once a year for the life of the study, and more often when the risks warrant it. At each review, the board looks at a progress report from the research team that includes a summary of any unexpected problems or adverse events that have occurred since the last check-in. If something has gone wrong, such as side effects occurring more frequently or more severely than anticipated, the IRB can require changes to the study, suspend enrollment, or shut the research down entirely.
Researchers are also required to report certain serious or unexpected events to the IRB as they happen, not just at the annual review. This real-time reporting allows the board to intervene quickly if participant safety is at stake.
Which Agencies Enforce IRB Rules
Two main federal agencies oversee IRBs in the United States. The Office for Human Research Protections, part of the Department of Health and Human Services, enforces the Common Rule, which applies to all federally funded research. The FDA enforces its own parallel set of regulations that apply to any research involving FDA-regulated products like drugs, medical devices, and biologics, regardless of whether federal funding is involved. When a federally funded study also involves an FDA-regulated product, both sets of rules apply simultaneously.
Outside the U.S., similar committees go by different names. In many countries they’re called Independent Ethics Committees (IECs), while Canada uses the term Research Ethics Board (REB). The function is essentially the same: independent review of research to protect human participants.
IRBs Beyond Medicine
Although IRBs are most closely associated with clinical trials and biomedical research, they review studies across all disciplines that involve human participants. A psychology experiment, a sociology survey, an education study collecting data from students, or a political science project conducting interviews all require IRB review if they’re conducted at a regulated institution. The threshold isn’t whether the research is medical. It’s whether the research involves people.