The present invention discloses novel peptides derived from the IL-1 receptor antagonist protein (IL1 RA), capable of binding to the cell surface IL-1 receptor 1 (IL1 R1 ) and interfere with the binding of IL-1 to IL1 R1. This binding thus effectively antagonises the inflammatory effects of IL-1, such as by reducing TNF-alpha secretion from macrophages. This is of potential use as an anti-inflammatory factor throughout the human body, including the central nervous system. The use of said peptides as anti-inflammatory agents for treatment of pathological conditions wherein IL-1 plays a prominent role, such as inflammatory conditions of the body and the central nervous system, is thus an aspect of the present invention.