Chief Physician, Professor, and Doctoral Supervisor. Dr. Hongjun Li specializes in assisted reproductive technology, male infertility, chronic prostatitis, impotence, premature ejaculation, and anejaculation, with a particular focus on the diagnosis and treatment of male climacteric syndrome. He has 21 years of clinical experience in andrology, having treated tens of thousands of patients. His expertise includes sexual and psychological counseling, erectile dysfunction, retrograde ejaculation, male gonadal dysplasia, male-related early habitual abortion, and complex andrological diseases. Originally from Kaiyuan, Liaoning, Dr. Li holds an MD in Urology and completed postdoctoral research in Andrology. He serves as a Professor and Chief Physician at the Department of Urology, Peking Union Medical College Hospital. He is an expert reviewer and editorial board member for several prestigious medical journals, including the Chinese Medical Journal and the Chinese Journal of Urology. He is also a committee member of the Reproductive Medicine Ethics Committee at Peking Union Medical College Hospital, a member of the Family Planning Branch of the Chinese Medical Association, and an expert at the Center for Drug Evaluation of the National Medical Products Administration. Dr. Li has led multiple research projects, published over 90 academic papers as the first author, and served as the editor-in-chief for numerous monographs and popular science books on andrology.