A humanized murine antibody is provided that binds to the human insulin receptor (HIR). The humanized murine antibody is suitable for use as a Trojan horse to deliver pharmaceutical agents to human organs and tissue that express the HIR. The humanized munne antibody is especially well suited for delivering neuropharmaceutical agents from the blood stream to the brain across the blood brain barrier (BBB). The humanized murine antibody may be genetically fused to the pharmaceutical agent or it may be linked to the pharmaceutical agent using an avidin-biotin conjugation system.