Associate Professor Christian Girgis is the Specialty Head of Internal Medicine at the Sydney Medical School, Faculty of Medicine and Health, University of Sydney. An endocrinologist, he holds qualifications including BSc(Med), MBBS (Hons), PhD from the University of Sydney, and FRACP. He completed his PhD at the Garvan Institute of Medical Research, followed by an NHMRC Peter Doherty Postdoctoral Fellowship at the Westmead Institute for Medical Research and a visiting scholarship at the Salk Institute of Biological Studies. Currently, he serves as Associate Professor (Teaching and Research) in the Westmead Clinical School and is the Program Director for the Master of Medicine in Internal Medicine. Clinically, Girgis runs the Osteoporosis and Metabolic Bone Disorders service at Westmead Hospital and acts as an honorary consultant in the Department of Endocrinology at Royal North Shore Hospital.

Girgis's research centers on vitamin D signaling, metabolic bone disorders, osteoporosis, fracture prevention, and novel therapies such as denosumab discontinuation strategies and sequential osteoanabolic treatments. His work integrates preclinical and clinical studies, advancing understanding of bone metabolism and skeletal muscle function. Key publications include 'The roles of vitamin D in skeletal muscle: form, function, and metabolism' (Endocrine Reviews, 2013), 'Vitamin D and Skeletal Muscle: Current Concepts From Preclinical Research' (JBMR Plus, 2021), 'Osteoporosis in the age of COVID-19' (Clinical Endocrinology, 2020), 'Denosumab discontinuation in the clinic: implications of rebound bone turnover and emerging strategies to prevent bone loss and fractures' (Journal of Bone and Mineral Research, 2025), and 'Balancing the risks and benefits of sun exposure: A revised position statement for Australian adults' (Photodermatology, Photoimmunology & Photomedicine, 2024). He leads interdisciplinary research efforts across university health precincts, fostering collaborations with major hospitals to translate findings into clinical practice and public health initiatives. In 2015, Girgis received the Endocrine Society of Australia Young Investigator Scientific Article Award.

Professional Email: christian.girgis@sydney.edu.au