Here are some basic facts about clinical trials:

Inpatient vs. outpatient trials

Inpatient clinical trials require that the subject (meaning you) stay at the facility for the length of the study, including overnight. Outpatient clinical trials require that the subject appear for the initial screening and trial start and then complete several follow-up visits.

Control vs. test group

Study participants are categorized into control and test groups. The control group is typically not administered the intervention and usually receives the placebo. Participants may also be recruited for the direct purpose of being part of the control group; for example, a study may need participants who do not have diabetes so that their responses can be compared to those participants who do have diabetes.

High pay

Clinical trials generally pay between $50-$300 per day/visit, with compensation dependant upon the length of the time required as well as the procedures performed. Overnight stays typically pay more money than those involving repeat visits. Likewise, the more invasive the procedures, the more monetary compensation that is provided. Aside from the money there are some major benefits to participating in clinical trials. For starters, clinical trials require that the subject undergo a physical examination. If it’s been a while since your last physical check-up, this is a good way to find out about your health. Drug trials often require more extensive examinations; you might be required to undergo an EEG, EKG, MRI or a complete blood analysis. The findings from such expensive tests can be invaluable for your personal health. Assuming you have a condition that is being studied in a clinical trial, that trial can even end up saving your life. Each year, thousands of cancer patients sign up for clinical trials in the hopes that such trials will cure or at least delay their cancer. However, even if all you have is a simple allergy, participating in a clinical trial that attempts to treat your condition can go a long way towards ridding you of this annoyance. Finally, there is the humanitarian aspect of participating in clinical trials. Without human test subjects, many currently successful treatments for HIV and AIDS would not exist. Likewise, many vaccines on the market today owe their realization to volunteers who willingly underwent testing. Medicine does not advance without the altruism of human test subjects. Here are some common questions answered!
  • You may gain access to new drugs and other treatments, sometimes years before they are widely available.
  • You will be monitored closely for any side effects.
  • You will have the chance to take an active role in your own healthcare.
  • You will be making a valuable contribution to research and may be financially compensated
  • A clinical trial can sometimes require more time and medical attention than normal care. This can include doctor visits, phone calls, more treatments, a hospital stay, or a more complicated treatment regimen. (Ask your doctor for information about the trial you are considering.)
  • The treatment might not work.
  • The treatment might cause serious side effects.
  • Even if a new approach helps some patients, it might not help you.
The definition of a healthy volunteer is pretty straightforward—it’s a volunteer that does not suffer from an ailment or condition. The volunteer literally is healthy. The trial may also require that the participant is not taking any medications. Healthy volunteers are essential to clinical studies, as they help provide comparison data for researchers studying the effects of drugs or other treatments on individuals with specific illness. If you qualify as a candidate for the study in question, they may ask you to be a participant in their clinical trial, depending on how many other individuals have volunteered and qualify.
Patients generally do not have to pay extra out-of-pocket costs for treatments studied as part of a trial. Every trial is different, but the clinical trial’s sponsor usually pays for all research-related costs and any special testing. Typically, the patient or his or her insurance company is asked to pay for any routine tests, treatments, or procedures that would be required as part of standard cancer treatment. Before you join a clinical trial, you will receive an informed consent document that spells out exactly what you’ll have to pay for and what you won’t.
All clinical trials have guidelines spelling out who can participate. These are called eligibility criteria. The factors that allow you to participate in a clinical trial can include age, gender, the type and stage of your disease, previous treatment history, and other medical conditions. Following eligibility criteria helps us keep you safe and ensures that researchers learn the information they need.
Yes. You can leave a clinical trial at any time and for any reason.
Every clinical trial must be approved and monitored by an Institutional Review Board (IRB) to make sure the risks are as low as possible and are worth any potential benefits. Once the trial is approved by the IRB, the organizers of the study must follow a careful plan, called a protocol, that describes exactly what will happen during the study. You will know the full details of the protocol prior to joining any clinical trial.
Informed consent is the process of learning about the clinical trial before you decide to take part in it. The research team running the trial will explain the trial’s purpose, how long it will take, what will happen, all potential risks and benefits, and information on the privacy of your medical records. If you want to participate, you will sign a consent form that details all of the information that has been discussed with the research team. You will be able to take that form home and refer to it at any time. Even though you have signed the consent form, you still have the right to leave the study at any time and for any reason. Informed consent continues throughout the trial. This will give the research team an opportunity to update you on the progress of the trial as well as any side effects or other risks that have been identified.
This depends on the study. Some studies pay hundreds or even thousands of dollars for participants. But you may have to go to weekly check-ins, get blood tests, take medications, and deal with side effects. Some of these studies can last months.

Who Can Join a Trial?

  • People of all ages, sex, race, or ethnic groups can be in clinical trials.
  • Some people are healthy, while others may have illnesses.
  • The kinds of people needed for a trial depend on the trial itself and the questions it is trying to answer.

Healthy Volunteers

A healthy volunteer is a person with no known significant health problem.
  • Some clinical trials include healthy volunteers.
  • Healthy volunteers usually do not get direct health benefits from joining a clinical trial.

Patient Volunteers

  • A patient volunteer has a known health problem. This person may join a clinical trial to help researchers understand or treat that condition.
  • While this person may get direct health benefits from joining the study, the main reason is to help doctors understand whether a treatment works or not.
  • Usually in Phase I and II studies, the participant gets the new treatment.
  • Usually in Phase III studies, some participants get the new treatment and others get a current treatment.
    • There is no guarantee that the participant gets one treatment or the other because a computer makes the decision by chance (randomly).
    • This is done to create a fair comparison between the new and the current treatments.

What does the “phase” of a clinical trial mean?

New treatments must pass through different phases before they can be released to the general public. If the treatment is successful in one phase, it will move to the next one. Patients typically participate in only one phase of a trial.


The first step in testing a new treatment is called a phase I trial. Phase I trials look at a new treatment to determine how well it works against a particular type of cancer, along with safety, best uses, dosage, and frequency of dosage. These early tests can carry significant risks. While the treatments that are studied are sometimes effective, there is no guarantee that they will work. For these reasons, phase I studies usually involve a small group of 20 to 80 patients. The first few people in a phase I study usually get a low dose of the new treatment. If there are only minor side effects, or none at all, the next few patients will get a slightly higher dose. This process continues until doctors find the dose that is most likely to work without causing severe side effects.


A phase II trial typically studies how well a new treatment works in a group of up to 100 patients with a similar type of cancer. Patients are treated using the dose and method found to be safest and most effective in phase I studies. Some phase II studies randomly assign patients to one of two treatment groups. This is called randomization and it helps doctors learn which approach provides the best balance of safety and effectiveness. These groups may receive different treatments, different doses of the same drug, or the same treatment delivered in different ways In many phase II randomized cancer trials, one group will receive the standard treatment while the other group receives the standard treatment plus the new treatment. Phase II trials may also look at the quality of life benefit offered by a particular treatment. In some cases, if a drug is successful in a phase II trial, the researchers may apply to the US Food and Drug Administration (FDA) to market it for doctors to treat the general public.


Phase III clinical trials compare new treatments with standard treatments, or compare new treatments with medical records from a group of patients who were observed in the past. In phase III trials, researchers are commonly trying to see which approach is safer and more effective. A phase III trial can include hundreds to thousands of patients. Each participant is randomly assigned to receive either the new treatment or standard therapy. In phase III studies, doctors typically look to see whether the new treatment gives patients a longer life, a better quality of life, and fewer side effects, and also shows fewer cases of cancer returning than standard treatment. In some cases, a phase III clinical trial can be stopped if the researchers notice that one group is doing significantly better than the other. If a drug is successful in a phase III trial, the researchers may apply to the US Food and Drug Administration (FDA) to market it for doctors to treat the general public.

Clinical Study Basics

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