The article discusses the regulatory challenges of phage therapy under EU pharmaceutical law. Phage therapy uses bacteriophages to target and kill pathogenic bacteria, but its legal classification and regulation remain unclear. The article examines whether phage therapeutics, whether derived from wild-type or genetically modified (designer) phages, fall under a specific class of medicinal products. It also explores the legal frameworks for the manufacture and administration of phage therapeutics, both pre-manufactured and patient-specific. The article highlights the need for a clear regulatory pathway to facilitate the successful translation of phage therapy into standard medical practice. It also considers the potential impact of upcoming legislative changes to Directive 2001/83/EC and Regulation (EC) No 726/2004 on phage therapy. The article concludes that phage therapy is not classified as a medicinal product under the current EU law, but its legal status may change with future regulatory revisions. The article also discusses the legal classification of phages, including whether they are considered cells, tissues, blood products, or medical devices. It further addresses whether genetically modified phages qualify as gene therapy medicinal products (GTMPs) and whether they are classified as genetically modified organisms (GMOs). The article emphasizes the importance of a clear legal framework to ensure the safe and effective use of phage therapy in human medicine.The article discusses the regulatory challenges of phage therapy under EU pharmaceutical law. Phage therapy uses bacteriophages to target and kill pathogenic bacteria, but its legal classification and regulation remain unclear. The article examines whether phage therapeutics, whether derived from wild-type or genetically modified (designer) phages, fall under a specific class of medicinal products. It also explores the legal frameworks for the manufacture and administration of phage therapeutics, both pre-manufactured and patient-specific. The article highlights the need for a clear regulatory pathway to facilitate the successful translation of phage therapy into standard medical practice. It also considers the potential impact of upcoming legislative changes to Directive 2001/83/EC and Regulation (EC) No 726/2004 on phage therapy. The article concludes that phage therapy is not classified as a medicinal product under the current EU law, but its legal status may change with future regulatory revisions. The article also discusses the legal classification of phages, including whether they are considered cells, tissues, blood products, or medical devices. It further addresses whether genetically modified phages qualify as gene therapy medicinal products (GTMPs) and whether they are classified as genetically modified organisms (GMOs). The article emphasizes the importance of a clear legal framework to ensure the safe and effective use of phage therapy in human medicine.