Core Viewpoint - The General Administration of Customs of China has outlined regulations and measures regarding the export declaration of fentanyl-related substances, emphasizing strict control and prevention of smuggling activities [1][2]. Regulatory Framework - Fentanyl-related substances such as alfentanil, fentanyl, sufentanil, and remifentanil are classified as narcotic drugs under the "Directory of Narcotic Drugs" (2013 edition) and are subject to management according to the Narcotic Drugs Management Law of the People's Republic of China [1]. - In 2019, fentanyl-related substances were fully regulated and included in the "Supplementary Directory of Non-Medicinal Narcotic Drugs and Psychotropic Substances," prohibiting any production, sale, transportation, use, storage, and import/export by individuals and organizations [2]. Customs Control Measures - The Customs authority maintains a high-pressure stance against the smuggling of fentanyl-related substances, employing various measures such as risk analysis, targeted inspections, and enhanced use of detection equipment like CT and X-ray machines [2]. - The Customs has optimized and upgraded intelligent imaging algorithms to improve the identification of concealed smuggling activities, ensuring timely human inspections of suspicious goods [2]. Personal Carry Regulations - Individuals carrying narcotic drugs and psychotropic substances for medical treatment must present a medical diagnosis certificate and identification, allowing them to carry a maximum quantity as per a single prescription [3]. - Medical personnel carrying small amounts of narcotic drugs and psychotropic substances for medical needs must hold a certificate issued by provincial-level drug supervision authorities, which Customs will accept for clearance [3].