Gender-InSIGHT aims to equip a new generation of interdisciplinary researchers with tools from disciplines including psychology, history, ethics, endocrinology, neuroscience, and public health. Through co-creation and mixed-methods research, doctoral candidates will increase understanding of the influence of biopsychosocial factors on gender during diverse hormonal transitions, including variations in puberty and menopause. Specific attention will be paid to groups historically marginalized in such research, for example trans and gender diverse people and those with variations of sex characteristics. Historical, clinical, and societal lenses will focus attention on, respectively, documenting the history and ethical implications of the shifts in meaning given to biopsychosocial factors in the framing of hormones and gender over time; providing clinical guidance informed by a biopsychosocial understanding of gender to assist patients and healthcare providers with decision-making regarding diverse hormonal transitions; and uncovering societal pressures and polarization regarding the biopsychosocial nature of gender and how these are communicated across cultures and through different channels. The training programme is designed to broaden and deepen interdisciplinary knowledge and to advance research skills, methodological expertise, and transferrable skills. Novel data, methods, and tools will be disseminated through a wide range of channels to ensure all stakeholders are reached. Collaboration with partners from non-academic domains promotes effective knowledge exchange and stimulates patient-provider engagement, collaboration in decision-making, and building infrastructure around research results of Gender-InSIGHT. This will have a lasting impact on culture and media, healthcare, and public policy and contribute towards EU goals to combat stereotypes and sexism, achieve gender equality, and ensure healthy lives and well-being for all.