Grounded in the biopsychosocial model and the Job Demands-Resources framework, this longitudinal study explored how physiological stress and psychological resources jointly shape cross-cultural adaptation among returnees and foreign talents in China. A total of 357 professionals, including both Chinese returnees and foreign experts, participated in this study by completing self-reported measures and providing hair samples for cortisol analysis. Six months later, 246 of these participants completed follow-up measures. The surveys administered assessed resilience, perceived talent status, coping strategies, and effort-reward imbalance. Results revealed distinct yet convergent adaptation patterns: returnees reported greater use of active coping, while foreign talents perceived higher talent recognition. Despite these differences, both groups reported comparable levels of resilience, physiological stress, and ERI. A moderated mediation analysis showed that elevated baseline cortisol predicted lower ERI at time 2, and individuals with low levels of resilience reported an increase in effort-reward imbalance. For highly resilient participants, ERI remained consistently low regardless of cortisol, reflecting a ceiling effect of psychological protection. Although perceived talent status independently reduced ERI, it did not significantly mediate the cortisol-ERI association. These findings support a dual-pathway model in which psychological resilience and physiological arousal operate as complementary, compensatory systems. As long as one pathway is engaged, individuals maintain a balanced effort-reward ratio and occupational well-being. This perspective challenges deficit-based views of cortisol and underscores the need to integrate both psychological and physiological resources in global talent management.