Tegileridine (艾苏特) is a small molecule μ-opioid receptor biased agonist developed by Jiangsu Hengrui Pharmaceuticals Co., Ltd for the treatment of postoperative pain. Tegileridine selectively activates the G-protein-coupled pathway, which mediates strong central analgesic effects and only weakly activates the β-arrestin-2 pathway implicated in adverse events like respiratory depression and gastrointestinal dysfunction. In January 2024, tegileridine received its first approval in China for the treatment of moderate to severe pain after abdominal surgery. This article summarizes the milestones in the development of tegileridine leading to this first approval for the treatment of moderate to severe pain after abdominal surgery.