Learn About Clinical Studies - What Is a Clinical Study? - Who
Conducts Clinical Studies? - Where Are Clinical Studies
Conducted? - How Long Do Clinical Studies Last? - Reasons for
Conducting Clinical Studies - Participating in Clinical Studies
What Is a Clinical Study? A clinical study involves research
using human volunteers (also called participants) that is
intended to add to medical knowledge. There are two main types
of clinical studies: clinical trials and observational studies.
ClinicalTrials.gov includes both interventional and
observational studies. In a clinical trial (also called an
interventional study), participants receive specific
interventions according to the research plan or protocol created
by the investigators. These interventions may be medical
products, such as drugs or devices; procedures; or changes to
participants' behavior, for example, diet. Clinical trials may
compare a new medical approach to a standard one that is already
available or to a placebo that contains no active ingredi