The drug development process is a lengthy process, and one of the longest, most expensive and significant stages is the clinical phase, whose purpose is to show that the drug is safe to use and effective. The first phase of clinical studies (Phase 1) is the first human study, and comes after laboratory and animal studies (preclinical). The second phase (Phase 2) is the phase in which the drug’s effectiveness in humans begins to be tested. Phase 3 is the last step before submitting the product for regulatory approval. Phase 3 is the most valuable and significant stage because testings is being done on a larger population and in multiple locations. Phase 4 (post-market) studies deal with collection of clinical data after marketing the drug, in order to complete and process information about the drug’s safety and efficacy.