Background <p>Premature ovarian insufficiency (POI) confronts cisgender women with menopause before the age of 40, placing them outside normative temporal expectations of the female life course. While its biomedical and psychosocial dimensions are well documented, less attention has been paid to how POI is shaped by age- and gender-based assumptions embedded in healthcare systems.</p> Methods <p>This qualitative study employed a constructivist grounded theory approach (Charmaz), based on narrative interviews with eight women who entered menopause between the ages of 23 and 38, to examine how embodied experiences, social norms, and healthcare encounters —informed by feminist phenomenology—intersect in shaping interpretations of POI.</p> Results <p>POI emerges as a profound temporal dislocation, with participants describing their bodies as ageing “out of sync” with their chronological age and social environment. This desynchronization disrupts biographical expectations and, in some accounts, crystallize into internalized ageism. Biomedical frameworks offer limited interpretive resources beyond deficit-oriented understandings, while healthcare encounters are frequently marked by misrecognition and epistemic injustice, as POI falls outside age-normative clinical expectations.</p> Conclusion <p>The article suggests that POI can be read as a site of age- and gender-based misrecognition, in which ageism manifests less through overt discrimination than through internalization and structural invisibility. Addressing these inequalities requires more inclusive clinical frameworks, improved psychosocial support, and greater recognition of diverse temporalities of ageing across the life course.</p>