This is the story of how a common ailment - the headache - became the centre of a multibillion dollar pharmaceutical industry in the United States. Despite the increasing authority of the medical profession in the 20th century, treatment of this condition has remained largely in the hands of the public. Using the headache as a case study, and advertising as a significant source of information, Jan McTavish traces the beginnings of the modern over-the-counter industry. The American pharmaceutical industry developed from 19th-century suppliers of plant-derived drugs for both professional and home care. Two branches of the industry evolved over time - the ethical branch, which sold products only with prescriptions, and the nostrum branch, which was noted for its energetic marketing techniques. At the end of the century, they were joined by German companies that combined a strong commitment to science with aggressive salesmanship. Since German drugs were both highly effective in treating headaches and commonly available, sufferers wanting quick relief could easily obtain them. The result was a new kind of "legitimate" pharmaceutical industry that targeted consumers directly.