Since the late 19th century, a transnational circulation of biomedical paradigms fundamentally reshaped the understanding of same-sex desire, transitioning from a model of vice to a categorization of pathological identity. Medical experts, including forensic physicians and psychiatrists, actively participated in the construction of the “homosexual” and the “invert” as distinct biological types. This epistemological shift moved scrutiny from the isolated sodomitic act to the essentialized individual, anchoring deviance in congenital traits, endocrine imbalances, or acquired neuroses. These discourses served broader biopolitical projects of social hygiene and national regeneration, positioning the physician as the modern arbiter of social order. By framing homosexuality as a contagion that threatened the vitality of the "race" and the stability of the bourgeois family, medical knowledge reinforced rigid gender norms and justified state intervention. While some early sexological models suggested biological innocence to argue against penalization, authoritarian regimes later weaponized these categories, reinterpreting non-normative sexuality as a “social danger” requiring confinement and cure. Ultimately, this medicalization did not displace moral judgment but scientized it, creating a persistent legacy where the management of sexual deviance became central to the definition of citizenship and public health. Consequently, this presentation aims to analyse how these knowledge producers actively participated in manufacturing the social and legal categories that shaped the perception of homosexuality. By investigating local reinterpretations of European scientific paradigms, we seek to demonstrate how the medicalization of sexuality functioned not merely as clinical observation, but as a biopolitical strategy to manage "deviant" populations and reinforce the social order.

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