When you hear about someone you know participating in a clinical study, it often is because the person is sick and is trying an experimental medicine or treatment because more conventional methods haven’t worked. However, there are thousands of clinical trials going on around the world every day, testing everything from skin creams to live-drugs to artificial parts. Clinical trials are an important part of drug development as well as other treatments.

Clinical drug development is a long process. It can take many years to get a drug from concept to approved treatment, and the clinical trial process is a big part of that process. Before a drug or any other medical treatment can get approval by the Food and Drug Administration, it has to go through a series of clinical trials.

The process starts off with a phase 1 clinical trial. This is the very first time a new treatment gets used in humans, and usually comes after animal testing has been done. In phase 1, a drug company or researcher is looking to see if the new treatment causes any side effects and whether it is safe. The treatment usually is tested on a small group of volunteers, usually about 20 to 80 people. These tests often occur at private companies that specialize in doing early phase drug testing, but they may also take place at hospitals or other centers.

If the phase 1 test proves that the drug or treatment is safe and has minimal and acceptable side effects, then it can move on to phase 2 testing. In phase 2, the drug or treatment is tested in a larger group of people, usually 100 to 300, with the main focus being on whether it works the way researchers expect it to. Safety is also a part of this phase of testing.

If a drug or treatment makes it to phase 3, then it will be tested on a much larger group of people, usually 1,000 to 3,000. At this stage, researchers are looking not only at effectiveness and safety, but also how the drug compares to other treatments, especially whether it works better or worse.

The whole process of medical research studies, including clinical trials, is by no means a slam dunk. In fact, it’s more like a complete long shot. Of the 5,000-10,000 new drugs that researchers come up with each year, only about five of them make it to the clinical trial stage and only one gets FDA approval. This helps to explain somewhat why new, effective treatments can be so expensive. With so many failures, companies have to make a huge amount of money on their few successful drugs to fund all the research and development activities.