Doctors' wellbeing is overlooked, although stress and burnout is high. Evidence suggests links between mentoring and health and wellbeing, but little is known. This mixed methods, Realistic Evaluation investigated relationships between mentoring by ‘trained’ mentors, and doctors experiences of health and well-being. Data included a questionnaire (n=57) and multiple interviews (n=43) with 13 mentors over 20 months. Findings identified many threats to doctors’ health and wellbeing. However, an ‘empowerer’ model of mentorship enacted via formal and informal interactions enabled constructive responses which go beyond individuals to groups, and appear to increase social capital, individual and group agency, resourcefulness and resilience