Introduction: Ageing is a biological process, but its meaning is socially constructed through cultural narratives that assign value and visibility. In contemporary societies, the "positive ageing" paradigm coexists with a coercive demand for eternal youth. This study examines The Substance (2024) as a cultural case study of gendered ageism and the social regulation of ageing female bodies.

Methods: A qualitative sociological analysis was conducted through a critical close reading of the film. The interpretation is guided by narrative gerontology, the notion of erotic capital (Hakim) to address the market value attached to female appearance, and the concept of abjection (Kristeva) to analyse the ageing body as a site of cultural anxiety. Analytical attention focused on four dimensions: (1) ageing as cultural construction, (2) the metanarrative of decline, (3) the individualisation of "positive ageing", and (4) gendered invisibility and aesthetic labour.

Results: The film depicts ageing not merely as a loss of status, but as the devaluation of the female body within appearance-centred cultural industries. It illustrates how "positive ageing" operates as a moralised form of self-management in which later life is framed as a personal failure to maintain desirability. A gendered double standard is intensified: while older men remain culturally legible, older women are rendered invisible unless they conform to restrictive youth norms through continuous bodily intervention.

Conclusions: The Substance foregrounds ageism as a structural form of gendered inequality. Challenging it requires deconstructing the narratives that equate ageing with a loss of value and expanding social spaces where growing older does not imply exclusion or the rendering of the ageing female body as monstrous.