Mark has been a director of Holdsworth House Medical Practice since its inception in 1992. His particular interests are holistic general practice, clinical research, HIV medicine, STIs, travel medicine, and hypnotherapy. He has completed his medical degree at University of Western Australia and Masters of Medicine in HIV and Sexual Health from the University of Sydney. He is a past President of the Sexual Health Society of NSW and past President of the Australasian Society for HIV, Blood Bourne Viruses, and Sexual Health. He is the director of the Clinical Research Unit at Holdsworth House, co-joint lecturer in Medicine at the University of NSW, and a member of medical advisory boards.