In this essay it is argued that advertisements for medicines in the lay press constitute an important source for the patient in medical history. At first sight, advertisements only seem to document the supply side of the medical market. However, the image of the proactive manufacturer offering his goods to passive consumers is a misleading one. For a manufacturer to get and remain in business, it was crucial to develop a sensitive antenna for the needs of the public. In a highly commercial domain like health care around 1900 production, distribution and consumption of medicines constituted an interactive cycle of which advertisements were a part. They mirror a subtle play with dormant notions about health, illness and healing. When looking at it this way, the health care system (or rather: the medical market) becomes a place where meaning is being constructed, negotiated and exchanged. Thus, by taking a closer look at advertisements, the demand side comes in sight as well. By using advertisements for medicines in the lay press as a source, it seems possible to overcome the objection that much patient history is still too much focused on the academy and on physicians.