Everything You Need To Know About Clinical Trial Phases Before Making Big Decisions

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Clinical Trial Phases—Everything You Need To Know Before Making Big Decisions

Clinical trials are an essential part of medical research that deals with finding new medication and ways of diagnosing, treating, and preventing illnesses and medical conditions. There are around 325,822 registered clinical trials, and the numbers are rising continuously. According to the Food and Drugs Administration (FDA), most drugs and treatments never go past the pre-clinical testing.

Testing new medication is a long and thorough process that can take ten years or even longer—as it includes four phases of testing.

What Are the Four Phases of Clinical Trials?

The four phases of clinical trials are connected, but every phase has a separate purpose. During these phases of clinical trials, scientists collect the essential data about how the new medication works, what effects it may have on people, and whether any side effects occur.

There are four official phases of clinical trials:

  1. Phase one
  2. Phase two
  3. Phase three
  4. Phase four

An additional phase of clinical trials that isn’t conducted often is the zero phase. This phase of a clinical trial is performed on such a small number of patients that its results don’t contribute much to the testing process on the whole. Phase zero is not required for the approval of the medication, and it’s frequently used to speed up the process of Investigational New Drug (IND) approval.



Number of Patients


  • Determining if the medication does what it’s supposed to
  • Testing how human cells react even though the doses are too small for the patient to experience the benefits of the treatment

Up to 15


  • Testing how safe the medication is
  • Testing what the safe dosage is
  • Monitoring the body’s reaction to the treatment and what side effects occur



  • Testing the effectiveness of the drug
  • Studying the short-term side effects
  • Testing different ways of treatment distribution

From a few dozen to 300


  • Gathering further evidence about the safety and effectiveness of the drug
  • Combining the new medication with existing ones
  • Testing how the medication affects different populations
  • Determining the right dose

From several hundred to 3,000


  • Determining the long-term effect of the medication
  • Testing the safety of the medication over a long period
  • Studying cost-effectiveness


Phase One of a Clinical Trial

Scientists use the first phase of a clinical trial to determine whether the drug is safe for humans and how the body reacts to the treatment. This phase of the testing is usually done on healthy volunteers who participate in clinical trials. The number of patients is small—from 20 to 80.

The purpose of phase one of the clinical trial is to determine any side effects and how the medication is metabolized by the patients. A team of medical professionals that work on the clinical trial monitor the subjects carefully because safety is the number one priority during phase one.

Another purpose of this phase is determining which dose is safe and beneficial to the patient. The dose is distributed little by little until the correct dosage is found.

You might opt for a clinical trial because you’ve already tried everything, but keep in mind that the first stage of clinical testing comes with the greatest risk because it’s the first time the drug is being tested on people. Nothing is certain and determined in the first phase.

Phase Two of a Clinical Trial

The scientists may start with phase two after they’ve concluded that the medication is safe for people and that they’ve established the right dose. During this phase, researchers aim to determine the effectiveness of the medication in people who have the disease, and they monitor the short-term side effects carefully.

This phase of testing is conducted on a larger number of patients—it can involve up to 300 people. Scientists compare the cases of patients who are on the clinical trial and receive the new treatment to others with the same or similar disease who receive a different treatment—whether it is standard or placebo.

At this stage, researchers also test the methods of drug administration.

Phase Three of a Clinical Trial

After the early phases of drug testing are done, phase three of clinical trials begins. With this phase, the number of subjects changes—mounting to over a thousand. The way the drug is distributed is established, and researchers determine if the medication is effective. Phase three of the test is conducted all across the country.

This is when are conducted. The test subjects are divided into groups at random, and scientists monitor the results to make a definitive conclusion about how effective the medication is compared to the standard treatment. The test group gets the new drug, and the control group gets the standard medication or a placebo.

Phase three can last up to four years, and it’s the most difficult trial to design along with being the most expensive.

Phase Four of a Clinical Trial

The fourth phase of clinical trials is conducted on a larger scale, and it can take up to 10 years, sometimes even more. The fourth stage can begin only after the FDA approves the New Drug Application (NDA). This phase is all about manufacturing the medication and supplying it to the wider masses—this phase includes several thousands of participants.

During the fourth phase of medical research, doctors can prescribe the new medication to you. At this point, there’s no doubt about the drug’s safety because it already underwent the previous three phases of testing. The fourth stage studies the effect of the drug in the long term.

How To Find Clinical Drug Studies With DoNotPay

You googled “clinical trials near me” and came up with nothing? Don’t worry, because DoNotPay has got you covered. The best way to find clinical trials without spending countless hours on Google is DoNotPay.

Access our app in your and follow the simple instructions listed below:

  1. Log in to your account
  2. Click on Clinical Trials
  3. Select Get Started
  4. Set the filters according to your wishes and complete a brief questionnaire
  5. Choose a study you want to participate in
  6. Click on Contact

Our app will find the best clinical trials, paid medical surveys, and university studies you can wish for, and all the money you earn is yours—we charge no fees or take any cuts. Our website has a clinical trials database that contains information about time, location, eligibility, and other details of the study.

Our app is always up-to-date, so you won’t miss any new studies.

DoNotPay will keep a list of all the studies you applied for on your dashboard, so you will be able to monitor your progress.

We will help you find clinical trials all over America—from Houston and Boston to Los Angeles—that deal with diabetes, depression, multiple sclerosis, and other illnesses.

Find Medication Clinical Trials in Other Ways

If you’re interested in being a part of such a noble cause as contributing to clinical trials, these are the few websites where you can search for them:

DoNotPay Is Noble—Like You—And It Will Help You Manage a Range of Issues

Other than helping you find clinical trials that work for you, DoNotPay can help with various other issues, such as getting you help with your medical bills and avoiding the consequences of not paying them.

If you want to cancel your online pharmacy like Express Scripts or CVS CarePass, you can do it with DoNotPay in five minutes. ED is no shame, and we can help you solve this slight bump in the road by helping you get a BlueChew free trial without being ripped off.

You can solve most of your issues by opening DoNotPay in your . We offer you help in:

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