Pros and Cons of Participating in a Clinical Trial

Con: The treatment may not work, or you could get a placebo

On the flip side, just because you enroll in a clinical trial doesn't mean you are guaranteed to receive the treatment that's being tested.

Many clinical trials compare the new treatment or intervention to a placebo. (A placebo is a substance that has no therapeutic effect, such as a sugar pill or saline solution shot.) So when you enroll in a clinical trial, you could be assigned to this comparison group, called the control group, and not receive any treatment at all. Other trials use existing treatments and interventions as the comparison group.

Also, the new treatment or intervention is not guaranteed to work better than a placebo or existing treatment.

Pro: Your health will be closely monitored throughout the study

Oftentimes patients first learn about a clinical trial through their own health care providers, and once enrolled they find that the trial's medical research team becomes like “an extension of their care team,” says Sumita Khatri, M.D., director of the Cleveland Clinic Asthma Center and a research subject advocate for the Clinical Research Unit at Cleveland Clinic.

With all of the extra monitoring and wellness checks, Clarke says volunteers may end up receiving “more comprehensive care in the trial than they would if they weren't participating.”

"It's a long process. It's an involved process,” Khatri says, “But because of the multiple visits, you're monitored way more than you would be as a layperson just, you know, walking around in the world.”

Con: You could experience unpleasant side effects or an adverse reaction

No matter how closely you are monitored, the drug or therapy being tested could cause an unpleasant side effect, ranging from minor (such as a sore arm at the injection site) to more severe, called an adverse reaction. (An example of this: AstraZeneca's phase 3 coronavirus vaccine trial was recently paused to investigate what the pharmaceutical company called “a single event of an unexplained illness,” widely reported to be transverse myelitis, a disorder caused by inflammation in the spinal cord. The trial has since resumed in several countries.)

It's important to note that most serious reactions and complications are typically discovered in the earlier phases of a clinical trial, when the safety of a drug or device is tested in a smaller population, Khatri says.

Also: Researchers are required by the federal government to follow strict protocols designed to protect the health and safety of study participants. This protocol is explained to prospective participants during the informed consent process, where members of the research team discuss the volunteer's role in the trial and any risks associated with participation. The NIH's National Institute on Aging (NIA) has a comprehensive list of questions to ask during this process (or any time when deciding whether to join a clinical trial).

If you choose to participate, you will be asked to sign an informed consent document. Sometimes researchers will mail this form to potential participants ahead of meeting in person, so the interested volunteer can have time to read and digest the information and discuss the trial with their loved ones, Yung says. However, the NIA makes it clear that the document is not a contract, and even after signing the consent form, participants “can leave the trial at any time and for any reason” without judgment or penalty.

"The fact that it is something new means that there is always risk, and a risk that we may not be able to anticipate,” Yung says. “And so you have to understand what risk level you are willing to take.”

Pro: Your participation could help others

There are benefits beyond the possibility of bettering your own health. Your participating in medical research allows doctors and scientists to learn more about a condition that likely affects a lot of people. And if it's a genetic condition being studied, your participation could affect others close to you.

"It's sort of an altruistic sense of being able to help others not to have to suffer through what [you] are suffering,” says Jay Magaziner, professor of epidemiology and public health at the University of Maryland School of Medicine and director of the Center for Research on Aging.

"I think that part of our responsibility, too, for being part of a thriving society is to think about not just ourselves, but think about what we can do to help others, especially in cases where it doesn't put us at undue risk,” he adds.

Con: Participating in a clinical trial can be inconvenient

Each trial has different requirements when it comes to time. Some studies last days, while others take years. Some require long in-person appointments and tests, while others can be done over the phone in a matter of minutes. So it's important to find out how much time the study will demand and decide whether you have that kind of time to spare.

A trial may also require travel to a medical center or research hospital. If that is the case, ask whether you will be reimbursed for gas and parking. Some clinical trials may even reimburse you for your time and participation, but this varies. (In rare cases, clinical trials may request that volunteers pay for participation. If this come up, there are certain guidelines researchers should follow.)

And if you can't drive yourself to the research site, ask about transportation options. The study coordinators may be able to make arrangements to get you where you need to be.