Clinical trials are the pinnacles of medical research. Through the last hundred years, investigators have learned best practices and what to avoid. The clinical research trial process is extremely lengthy and thorough, but it ensures patient safety and scientific understanding. Each step is designed to minimize harm, maximize transparency, and build trustworthy evidence that can guide healthcare for years to come.
Table of contents
Designing the Experiment
Forming a research question and creating a safe and robust plan to solve it is the first but trickiest step of a clinical research trial. Investigators must also determine their selection criteria and develop ways to screen patient volunteers, including people who are to be in their control group. It’s imperative that patients provide informed consent throughout this entire process, and that consent is continuously revisited if procedures or expectations change.
Researchers must also clearly articulate how they will administer the treatment, what doses they’ll start with, what data they’ll collect, and how they’ll review and analyze that data. This planning phase can take months or even years because clinical teams must align on variables, refine definitions, anticipate potential risks, and build strong safeguards. Rigorous preparation dramatically reduces errors later in the trial and helps preserve both scientific integrity and participant welfare.
Getting Approval
There are two main ways to get approval before starting a clinical trial. The first is through an Investigational New Drug (IND) Application. The FDA reviews this application to evaluate any relevant data from previous animal or human research, how to make the drug, the research protocol, and background information about the investigators. Clinical trials must also get approval from an Institutional Review Board (IRB) to ensure participant safety and informed consent. In many cases, researchers may need to respond to questions, provide clarifying documentation, or revise parts of their protocol to meet regulatory expectations. This back-and-forth can be lengthy, but it helps ensure the study is ethically and scientifically sound before a single patient is enrolled.
Conducting Trial Phases
After approval, experiments can now begin. These clinical trials can take many years to complete. In general, the steps of a clinical research trial involve exploring different research questions throughout the different phases:
Phase I
- Is the treatment safe?
- What dose is appropriate?
- What are the short-term side effects?
Phase II
- What are the long-term side effects?
- Does the substance work as a treatment for the condition?
Phase III
- Are these results replicable across larger populations?
- How does this experimental treatment compare to the standard treatment?
Phase IV
- What are the effects on different people over time?
- What is the efficacy, or what are the long-term benefits?
- What are the long-term risks?
- How will health providers use this treatment?
Monitoring and Ethical Oversight During the Trial
Once a clinical trial begins, the work is far from over for researchers and regulatory bodies. Throughout every phase, independent committees—often called Data and Safety Monitoring Boards (DSMBs)—regularly review collected data to ensure the trial remains safe and ethically sound. These boards have the authority to pause or stop a study if unexpected risks arise, if early data shows the treatment is clearly ineffective, or if the results are so positive that continuing the trial would withhold benefit from the control group.
Researchers must also document every adverse event, whether minor or severe, and report it promptly to oversight agencies. Transparency is a central pillar of clinical research, and maintaining meticulous records protects both participants and the integrity of the data. Ethical oversight doesn’t end with protocol approval; it is an active, ongoing responsibility. This continuous monitoring ensures participants are respected, protected, and informed throughout the entire study, reinforcing trust between the scientific community and the public.
Conclusion
Learning the basics of how clinical research trials work is helpful even if you aren’t an investigator or a volunteer. These studies form the scientific backbone of modern medicine, shaping everything from routine prescriptions to breakthrough therapies. By understanding how carefully these trials are designed, approved, and executed, the public can better appreciate why medical research takes time—and why that time matters. Clinical trials ultimately protect patients, advance innovation, and ensure that new treatments are both safe and effective before they reach the wider world.
