Navigating Masculinities: An Exploration of Peer Coaching, Health Behaviors, and Mortality Risks Among Men in Tuberculosis and HIV Interventions in South Africa.

South African men remain disproportionately affected by tuberculosis (TB) and HIV, with social norms around masculinity often hindering care-seeking and medication adherence. This study investigates how Coach Mpilo, a peer mentoring intervention led by men who are TB survivors or living openly with HIV, engages concepts of masculinity to improve health outcomes among men in TB/HIV care. We conducted in-depth qualitative interviews with male peer coaches implementing the Coach Mpilo intervention in Eastern Cape, Western Cape, and KwaZulu-Natal provinces. Coaches, all TB survivors and/or living with HIV, described their experiences supporting newly diagnosed men with TB/HIV. Guided by the Health, Illness, Men, and Masculinities Framework, thematic analysis identified key domains through which masculine norms and social expectations influenced health trajectories and intervention engagement. 20 participants described how men's emotional health is constrained by norms discouraging vulnerability. Participants reported that men's self-reliance and clinic avoidance impede timely care and adherence, and how provider roles, poverty, and structural barriers increase risk, often forcing men to choose work over health care. Coaches discussed hegemonic ideals among their peer clients, and that stigma delays diagnosis and worsens outcomes. Coaches described finding success by framing treatment and health-seeking as acts of strength and responsibility, and by advocating for male-centered clinic spaces and tailored support. Findings illustrate that working with, rather than against, masculine norms can motivate men to engage with TB/HIV services. Peer coaching that reimagines vulnerability as strength, while addressing both social and systemic barriers, holds promise for promoting men's health and reducing disparities in high-burden settings.