Phases of Research
Research studies are generally divided into the following four phases:
Phase I trials are designed to confirm the safety of a new medication/treatment. Phase I trials generally involve a small group of healthy volunteers and typically last three to four months.
Phase II trials help to confirm whether a medication/treatment is effective. These studies are randomized. Randomization means that participants are divided into two groups, with one group receiving the active treatment and the other group receiving a "control" (usually the standard treatment available).
Phase III trials are initiated once a medication/treatment has demonstrated initial safety and efficacy. Phase III trials help determine the efficacy of a medication/treatment over an extended period of time. These trials take longer and have a greater number of participants. Phase III trials can provide enough data for a product to be submitted for approval by the Food and Drug Administration (FDA).
Phase IV clinical trials are conducted to obtain additional information about a new medicine that has been submitted for FDA approval. Phase IV trials may also be conducted when a company is gathering more information about a product already on the market.