What is a clinical trial?

A clinical trial is a form of scientific research that involves human volunteers. These trials are vital to the field of medicine to gather safety and efficacy data of new drugs, devices, techniques, and more.

Before human testing is performed, drugs and devices typically undergo extensive laboratory testing that can last for years. If the research is successful, then the data is sent to the Food and Drug Administration (FDA), where it is reviewed and approved for continued research and testing in humans.

Clinical trials with human volunteers typically involves four phases:

  • Phase I: This phase includes a small group of healthy volunteers. A study may examine the effects of the product and how it is absorbed, metabolized, and excreted. Participants in the study are typically paid.
  • Phase II: The product is then given to a larger group of people, and it is evaluated for safety and efficacy. Trials are typically randomized – one group receives the investigational product, and another group receives a standard treatment or placebo. The studies may also may be blinded, which means that neither the patients nor the researchers know who has received the new product and who has received the placebo.
  • Phase III: This phase involves large-scale testing that can last for several years. Anywhere from hundreds to thousands of participants are enrolled in these studies. This phase offers even more insight into the product's safety, efficacy, and potential for adverse effects. After Phase III testing is complete, a company can request FDA approval for the product.
  • Phase IV: These studies are conducted after the FDA approves the product for sale. These typically evaluate a product's long-term efficacy and compare the product to others already on the market.

Researchers are required to submit data to the FDA after each phase, before continuing to the next step.