If you decide to participate in a clinical trial, you may be involved in one or more different phases of the research process. The research staff can discuss with you the phase being studied, and any known side effects suspected from the drug or treatment.
Phase I trials are designed to confirm the safety of the drug or treatments and for the first time it is tested in humans. Phase I trials generally involve a small group of healthy volunteers and typically last three to four months.
Phase II trials help to confirm the safety of drugs or devices in patients with the illness being studied. These studies are "randomized." Randomization means that participants are divided into different groups-one group receives the active treatment and the other group receives a "control," usually the standard treatment or placebo. This phase may last until the drug or treatment is approved by the Food & Drug dministration (FDA).
Phase III trials are initiated once a treatment has demonstrated to be safe. Phase III trials help determine whether a medication is effective over a longer period of time. These trials are longer and larger, in terms of the 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 more information on a new medicine that has been submitted to the FDA for approval. Phase IV trials are also conducted when a company is gathering more information about a product already on the market.