For nearly two hundred years, the United States Pharmacopeial Convention (Convention or USP) has worked to set quality standards for drugs (medicines and their ingredients). Much has changed during that period, including the globalization of the pharmaceutical industry, ongoing availability of better drugs to promote health and treat disease, demands for access to good quality medicines, systems that deliver interchangeable multi-source products after periods of patent and market protection, advances in measurement and manufacturing science, and calls for regulatory and compendial harmonization. In these contexts, USP’s public standards continue to play an important role in assuring both practitioners and patients that the medicines they use are of good quality relative to their safety and efficacy. If anything, recent events such as the rise in counterfeit and substandard medicines and adulteration crises (diethylene glycol, melamine, heparin) have heightened concerns about the quality of drugs, and reinforced the importance of USP’s public standards as part of the safety net that protects practitioners and patients in the U.S. and elsewhere.