Frequently Asked Questions

Before enrolling in a clinical trial it is important to get answers to any questions you may have.

Below we have provided answers to frequently asked questions regarding clinical trials so you are equipped to make an informed decision about you or your loved one's participation.


Clinical trials are a critical component in the process of developing a new drug or therapy. Clinical trials help drive the understanding of how effective a medicine is and how safe and tolerable it is.

Search for a clinical trial that may be right for you or your loved one here.

Anyone that meets the eligibility criteria for a particular study can potentially participate in a clinical trial. In order to determine eligibility, participants will undergo a screening process through which a doctor will assess whether or not they align with the clinical trial’s protocol.

No; you can reach out to and work directly with the clinical trial site in your area.

Every clinical trial is different and will vary in length depending on the study design of that particular trial. You will be informed about the specifics of the trial you are participating in as part of the informed consent process.

Clinical trials take place at trial sites, which can include hospitals, universities, doctors’ offices, or other medical centers. Clinical trials may happen at one site, or many sites at the same time. Each location is supported by a full research team.

The requirements for joining a clinical trial are known as “eligibility criteria”, and set parameters for the types of participants that are eligible for that particular study. Eligibility criteria may define gender, age, type of disease, stage of disease, treatment history, etc.

Researchers define “inclusion criteria” as the requirements a person must meet in order to be in included in a clinical trial. Maintaining inclusion criteria helps researchers ensure the purity of their data. Researchers also define “exclusion criteria” as requirements that may prevent a person from participating in a trial.

Children can be enrolled in clinical trials when the study is designed to include them. A study’s eligibility criteria will identify the appropriate age range.

The regulations and ethical standards for pediatric trials are very strict, to ensure the protection of the children participating.

Children are important for clinical trials because their bodies are still developing, and they react differently to medicine than adults do. There are a number of diseases that occur only in children, especially rare diseases, so including children in clinical trials is critical to advancing the treatment options available to them.

When you participate in a clinical trial, the treatment being studied may prove to be less effective than other treatment options or may have unexpected side effects.

By participating in a clinical trial, you can have access to a new treatment option before it becomes widely available. You also play an important role in helping new treatment options become approved for use.

These discoveries can not only benefit the people participating in the study, they can also have more far-reaching benefits for others, including those who are currently living with a specific disease or condition, and future generations as well.

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It is beneficial to learn as much about the study as you can before enrolling. The Center for Information & Study on Clinical Research Participation (CISCRP) provides a comprehensive list of questions for patients, parents, potential study volunteers, and other family members or friends to ask the research staff prior to joining a clinical trial.

Some trials may pay for certain associated travel costs, time, and commitment, but not all trials do. The amount of compensation varies in every case.

Each clinical trial is required to follow strict guidelines that pertain to that specific study, known as a protocol. This outlines how the trial will work and provides instructions that everyone involved in the trial has to follow.

These guidelines are approved by a government organization or a review board before the trial begins and monitored throughout; this ensures that participants in the study are treated fairly, that the study design is safe, and that the treatment studied has potential benefits that outweigh the risks.

Many individuals are involved in a clinical trial, and each has an important role in the overall success of the trial. A few notable positions include:

The principal investigator, who is the researcher or healthcare provider who leads the study. This person heads the research team made up of doctors, nurses, and other healthcare professionals.

The study coordinator, who works closely with the principal investigator and oversees the research team and participants.

The ethics review board, which is a group of individuals who review and monitor the study to ensure that the volunteers who participate in the study are protected and treated fairly.

Learn more about who else is involved in clinical trials.

Participants are allowed to drop out of a trial at any time, even if it is not yet completed.

Yes, patients can continue to see their usual doctor and broader care team at any point during their trial. Other healthcare providers may also work with the trial’s research team to ensure other medications and treatments do not interfere with the clinical trial protocol.

Patient privacy and confidentiality is a top priority in clinical trials, and the appropriate security measures are taken to ensure that personal health information and trial records are protected. When trial results are published in scientific studies, participants remain completely anonymous.

Attending every visit helps your research team follow your progress over the course of the study, and it helps them gain a better understanding of the study results.

It is important to continue to attend all visits even if your study team decides that you should stop taking the study treatment before the study ends.

After the clinical trial has finished, participants will be offered ongoing medical care through the primary healthcare providers.

Learn more about what happens after a clinical trial.

Legally, you have no obligation to tell your employer that you are participating in a clinical trial. It is entirely up to you whether or not you inform them.

Clinical trial results are often published on or in peer-reviewed scientific publications, regardless of outcome.

PTC has created a tool to help better understand scientific publications, and can be downloaded here.

A clinical trial is a research study used to validate a new treatment or therapy in volunteers young and old. By conducting these studies in controlled environments, researchers and medical professionals can determine if a treatment is safe and efficacious, and how it can be used to treat a specific disease or condition. For these reasons, clinical trials are a vital component in the advancement of medicine. Learn more about clinical trials.

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Prior to enrolling in a clinical trial, the process of “informed consent” provides participants with specific information related to the study. In the process, the clinical research team communicates the potential risks and benefits of participation.

All clinical trial participants must sign an informed consent form, indicating that they’ve been made of aware of the purpose of the trial and it’s risks and benefits. This form is not binding, and does not mean a participant must stay in the trial.

When a clinical trial is randomized, participants are allocated at random to the different arms of the study.

Certain clinical trials are designed to be “blinded”, or more specifically “double blind”, which means that both the study participants and the healthcare professionals administering their treatment are unaware of which treatment arm participants are assigned to.

The “placebo” is an inactive treatment or substance designed to look the same as the treatment being administered in the clinical trial and is used to compare the effects of the active treatment. In certain studies, some participants may receive a placebo instead of an active treatment.

The “control” or “control group” is a group of participants within a study that receive a placebo or the current standard of care, in order for researchers to have an arm to compare the study treatment to. This comparison helps researchers understand if the treatment being studied is effective and, in some cases, is better than the current standard of care.

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