Clinical trials are studies that use human subjects (people) to see whether a drug is effective and what side effects it may cause. The trials are for gathering information about a drug that has not yet been proven to treat patients with a specific condition. A drug being studied in a clinical trial is called an investigational drug.
Clinical trials of drugs provide information about:
Whether the drug has the effect it is supposed to have.
How much of the drug to give to a patient and how often.
What side effects are associated with the drug and how they can best be managed.
How a drug is broken down in the body, and how long it stays in the body.
Which foods, drinks, or other drugs can be used at the same time or should be avoided.
Clinical trial results allow the FDA to make decisions about whether or not a drug should be approved for marketing.