Purpose: The article investigates the evolution of document supply of print serials. Approach: The study is based on data from INIST-CNRS - document supply requests and access to electronic resources - of 95 serials with JCR impact factors in pharmacology. Data were collected from 1992 to 2003. Findings: The results distinguish four groups of serials each with a different evolution of supply requests. Nevertheless, the overall decline from 1999 is a global phenomenon linked to growing access to online journals and there seems little likelihood of a slowdown for the next few years. Originality: This is the first of three articles on a longitudinal study over 12 years on different aspects of the relationship between document supply and impact factor (citations) in pharmacology, a scientific domain with a high use of scientific information.