Before any new medication or treatment can be administered to patients, it needs to undergo several clinical trial Phases which test the treatment for effectiveness and safety. Clinical trials conducted by clinical research organization companies can take on an average six to seven years, with each individual Phase taking a different amount of time.

Phase 1 Trials

Phase 1 trials are generally completed within a year. The primary purpose of this Phase is for CRO clinical research companies to test for safety and the treatment is administered on healthy participants.

Phase 2 Trials

In this Phase of the trial, both safety and effectiveness are measured by clinical research organization companies.

Several hundred patients with the condition for which the treatment is being developed are recruited. This Phase typically lasts from several months up to two years.

Phase 3 Trials

In Phase 3 trials, the largest number of participants are recruited by CRO Companies to test the potential treatment. This Phase also measures safety and effectiveness, the difference being that many more volunteers, sometimes thousands are recruited.

Phase 3 trials last between one to three years. After Phase 3, a pharmaceutical company can submit an NDA or New Drug Application for the medication or treatment to Regulatory authorities such as the Food and Drug Administration (FDA). The Regulatory Authorities review results from all Phases of a clinical trial to determine whether the drug or treatment is suitable to be marketed to the public.

Phase 4 Trials

Once the drug is approved, it may move on to Phase 4 Trials where the long-term side effects of the drug or treatment are monitored among patients. This Phase is also the post-marketing trial and the timeframe is longer than other Phases and can vary significantly from one trial to another. People seeking to participate in a clinical trial need to be prepared to be prepared for frequent visits every few months and weigh the potential participation benefits against the time it requires. When choosing to join clinical trials, participants can choose to leave at any time and for any reason. Some trials may also end early if researchers do not see the results they were expecting.