Coping with a chronic disease can be a difficult time for everyone involved. Depending on the situation, patients can feel restricted by the lack of viable treatment options. One alternative method of therapy often explored is the use of experimental drugs. These drugs are categorized as medicines that have not yet be approved by the Federal Drug Administration (FDA) for consumer release.



The FDA approval process for prescription medication can span 10 to 15 years depending on the medication. This can be a substantial waiting period for patients who face limited windows of treatment for their disease. By participating in the clinical trials of an experimental medicine, the patient is afforded an opportunity to try new treatments that would normally not be offered. Though the nature of clinical trials comes with substantial risk, some patients are willing to assume this chance in hopes of finding a cure. An important aspect in measuring this risk is to understand the phases of testing. The four phases of clinical drug trials are examined below.

Phase 1 Trials

The goal of a Phase 1 trial is to measure the general safety and tolerability of the chemical compound. This is the first step in determining the suitability of a medication for use in humans. The research is focused on dosage thresholds and identifying side effects, and typically last 6 to 12 months. Phase 1 trials are considered very unstable and risky. Because of this, they are normally carried out on healthy adults.

Phase 2 Trials

The directive of a Phase 2 trial is to determine whether or not the medication has the desired effect on a particular condition. These trials are usually setup as blinded experiments where multiple drugs and a placebo are randomized between subjects. Neither the subjects nor the administrators are aware of which method of treatment a subject receives. This allows researchers to measure the effects of multiple treatments against each other. Phase 2 trials can last up to 2 years are conducted with subjects suffering from the target ailment.

Phase 3 Trials

Phase 3 trials are similar to Phase 2 trials in that they are used to measure the effectiveness of the experimental drug on the targeted condition. The difference between the two phases is that Phase 3 is conducted with a much larger sample size and the trial period can last over 3 years. This longer trial period allows for the study of long-term side effects and provides a better analysis of suitable dosage ranges. Phase 3 trials also draw in-depth comparisons to existing drugs in order to measure the inherent value of the experimental medication. The results of Phase 3 trials are used to determine accurate prescription dosages and consumer label information. Successful completion of this phase leads to an FDA submission for approval.

Phase 4 Trials

The final phase of a clinical drug trial is used for further testing of the medication. While an experimental medication may not yet be approved in the early stages of Phase 4 testing, it is generally deemed safe for targeted use. Even after the drug receives FDA approval, this phase continues as a requirement by the FDA. Long term testing continues to evaluate to safety and effectiveness of the drug, and alternative uses of the drug are also examined. Phase 4 trials are also used to test different methods for administering the medication. Thus, this final phase of trials can produce significant changes in the way a drug is used and how it is delivered.