There’s no way to eliminate all risk in clinical trials. But there are safeguards in place to maximize patient safety in all phases of clinical trials.

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If you’ve ever considered joining a clinical trial for a medical condition, you may have wondered whether they’re safe. The answer isn’t straightforward. Some carry a bit of risk, and others bring more. But the benefits may outweigh the risks.

Clinical research trials are studies that seek to test new medications, products, or procedures in people. They seek to answer questions such as:

  • Is this new treatment helpful?
  • Do its benefits outweigh its risks?
  • Can this new approach treat or cure a condition or ease symptoms safely?
  • How should people use this approach?
  • How does this new treatment compare to existing treatments, if any?

The level of risk depends on the trial and what product, service, medication, or intervention researchers are testing.

There’s no way to eliminate all risks, however minor. But there are many ways researchers and government agencies try to minimize risk and ensure patient safety.

Researchers help to ensure safety by following government regulations and by:

  • creating a research plan called a protocol
  • forming an institutional review board (IRB)
  • forming a data and safety monitoring board (DSMB)
  • getting your informed consent
  • reporting results to the Food and Drug Administration (FDA)

Let’s take a close look at some of these protections.


For starters, every clinical trial has what’s called a protocol, or plan, that spells out the study guidelines. That plan includes:

  • the purpose and goals of the trial
  • the types of volunteers needed
  • how researchers will conduct the study
  • how they’ll monitor the safety of trial participants
  • the medications, devices, or methods involved
  • the type of information they’ll collect
  • how long the trial will last

If the study has an IRB, the IRB looks at the protocols and makes changes or offers guidance before the study starts.


The job of the IRB is to review and approve a detailed research plan. The board’s goal is to protect the people involved in the trial. According to the National Cancer Institute, IRBs can include:

  • scientists
  • doctors
  • clergy
  • patient advocates

At least one member of the IRB needs to be a non-scientist who’s not affiliated with the institution.

The IRB ensures that the trial is legal, ethical, and well-designed. They also ensure that the plan doesn’t involve any unnecessary risk and includes a safety plan.

Every healthcare facility that does clinical research has an IRB. The institution’s IRB will review each trial before it starts.

But not every clinical trial has an IRB. Different institutions have their own guidelines as to when they require a trial to have an IRB. But in general, a clinical trial must have an IRB if the trial is studying an FDA-regulated drug, product, or device, or if it’s funded or carried out by the federal government.

The Office for Human Research Protection (OHRP) may provide guidance and oversight for IRBs.


In addition to an IRB, some trials set up a DSMB. It may also be called a data and safety monitoring committee (DSMC) or data monitoring board (DMC). This group includes experts in the condition and the population involved in the study.

From time to time, the DSMB will review data from the research, with a specific focus on patient safety. DSMBs can see more data than IRBs, so they can better assess safety. A DSMB can recommend a trial stop if there’s evidence that the trial causes harm.

The IRB will review the DSMB’s plans and recommendations in its own review of the study.

All phase 3 (later stage) clinical trials require a DSMB. While not required, the FDA comments that some trials in phases 1 and 2 may benefit from DSMBs. Some research suggests that the FDA should extend this requirement to early-phase trials as well.

All members of a DSMB must be independent. That means they’re not connected to the institution or sponsors of the research in any way.

Informed consent

The FDA requires researchers to get informed consent. That means that they must obtain your consent to participate and must make you aware of the details of a trial, including:

  • the interventions or procedures you will undergo
  • the trial research plan (protocol) and how it works
  • any possible risks or discomforts
  • the fact that participation is voluntary

Trial reporting

Researchers must report certain types of clinical research to, an online database of studies and their outcomes. The National Library of Medicine maintains the site, which contains research from all over the world.

In general, study authors must report on any research that involves an FDA-regulated drug, product, or device as long as any of the research takes place in the United States or involves a U.S. product. also contains many studies that authors aren’t required to report. These include observational studies and studies that aren’t looking into a drug or medical device. According to the website, researchers from all 50 states and 221 countries have reported their work in the database.

Some clinical research trials carry only minimal risk. Others may have more risk, and study organizers must tell you the risks before the trial begins.

Minimal risk means that the likelihood of harm or discomfort during the trial is not worse than anything you’d typically experience in daily life.

Besides minimal harm, some drawbacks of clinical trials to consider are:

  • You might not benefit from the intervention or product the trial is studying.
  • Study procedures might be very different than standard medical care.
  • The study might expose you to unknown risks.
  • There might be costs associated with the trial.

Researchers often conduct clinical trials in different phases. This is especially true for experimental drugs.

Phase 1

Researchers test a new drug or treatment for the first time in a small group of regular volunteers without the disease or condition. The group is usually between 20 and 80 people. The researchers look at the safety of the intervention and try to figure out a safe dosage and identify any side effects.

Phase 2

A larger group of people, usually in the hundreds and including people with the disease or condition, tries the medication or intervention. Researchers will again assess its safety in this group.

Phase 3

Thousands of participants try out the new treatment to make sure it works. The larger sample size allows researchers to identify most of the common side effects. They’ll also compare it to other medications for the same condition.

Phase 4

Researchers conduct these trials after the FDA approves the intervention and its public marketing. Participants continue testing the drug’s effects in various populations and get more data.

Each phase carries its own risk, but more unknowns exist when research begins.

Supporters of clinical trials say they benefit participants and others needing treatment for a medical condition. Trials help create new research and possible solutions to common medical problems.

Participants also benefit from early access to new medications and treatments and may experience more medical care and attention.

Do clinical trials use placebos?

Yes, some clinical trials use placebos. A placebo is a pill or other intervention that has no active ingredient or benefit but appears to be a genuine treatment. People in the trials don’t know who gets a placebo or the real thing. This is called blinding.

A placebo allows researchers to compare the effectiveness of an intervention versus no intervention and the placebo effect.

Will my information be kept confidential?

Your information is protected unless you agree, in writing, that researchers can disclose it. The Health Insurance Portability and Accountability Act of 1996 (HIPAA) protects your information, including during clinical trials.

HIPAA is a federal law creating national standards to protect sensitive patient health information. It prevents others from disclosing your information without your consent or knowledge.

There are limited, narrowly defined circumstances in which researchers can use your information without your authorization, mainly to assist in research. The Department of Health and Human Services (HHS) has a detailed list of exceptions on its site.

Do I have to pay for clinical trials?

Some clinical trials allow you to participate at no cost. Others can carry costs, but your insurance might pay for them.

According to the National Cancer Institute, your insurance company will often cover patient care costs. These include:

  • visits to your healthcare professional
  • stays in the hospital
  • standard cancer treatments
  • treatments to improve cancer symptoms or to ease side effects
  • lab, X-ray, and imaging tests

But insurers may not cover some research costs, such as:

  • the study drug
  • tests performed just for research purposes
  • additional imaging and X-rays only for research purposes

Questions to ask your doctor

A lot goes into deciding to participate (or not) in a clinical research study. Here are some key questions regarding trial safety to discuss with a healthcare professional:

  • What’s the purpose of the study, and who is funding it?
  • Who has reviewed the study plan?
  • What kind of therapies, procedures, and tests will I have?
  • How will my results and safety be monitored?
  • How long will the study last?
  • What are the possible short- and long-term benefits of this new treatment?
  • What are the potential short- and long-term risks of this new treatment?
  • How will the study affect the care I’m already receiving?
  • Who will be in charge of my care?
  • How will participation affect my personal life (e.g., time and transportation commitments, financial obligations)?
  • What are the costs, if any? Will my health insurance cover them?
  • What are my treatment alternatives?
Was this helpful?

If you’re looking to participate in a clinical trial, there’s a simple tool to help you. The National Library of Medicine has a search tool that allows you to find clinical trials that are recruiting or may be recruiting in the future.

The database is searchable by condition and country.

Diversity in clinical trials

The results of clinical trials can decide which new medical interventions the public may access later. There are many volunteers for clinical trials, but they don’t always reflect the diverse U.S. population. Trial groups often need to be more racially, ethnically, or socioeconomically diverse.

Lack of diversity in trials can have implications for your health. Medications and interventions affect people of different backgrounds and traits differently.

That’s why the FDA encourages people of underrepresented and historically marginalized groups to take part in clinical trials.

An FDA study of more than 100,000 U.S. clinical trial participants from 2015 to 2019 showed that 78% of people were white and 79% were over 65.

Was this helpful?

Clinical trials offer opportunities for volunteers to participate in studies that look at how effective new treatments might be. Several groups, including government agencies, set rules to ensure your safety is a priority. Even so, they can’t eliminate all risks.

Different trials carry different levels of risk. It’s helpful to talk with a healthcare professional to determine whether the possible benefits outweigh the risks.

Trial participation is voluntary. Volunteers tend to be mostly white and older. Greater diversity in trials can help improve the quality of the results.