Theory of Constraints (TOC) is a philosophy of management put forth by Eliyahu M. Goldratt, which claims that each system has at least one constraint. This philosophy is applied in many functional areas of companies, ranging from production flow management, marketing, accounting or project management to being a tool of logical reasoning. In this paper, the authors show how the Theory of Constraints can be applied in supply chains, with special attention paid to TOC-based stock management principles which are implemented in the pharmaceutical industry. A practical example described by the Authors illustrates the possibility of creating hybrid solutions combining TOC with other methods.