Perspectives on tissue-selective insulin derivatives.

Insulin is a central regulator of metabolic homoeostasis with diverse, tissue-specific actions across multiple organs. Despite major advances in insulin formulations, current therapies rely on systemic delivery and do not reproduce the physiological distribution of endogenous insulin, resulting in non-physiological tissue exposure and associated metabolic limitations. In this perspective, we discuss emerging strategies aimed at achieving tissue-selective insulin action, including molecular engineering of insulin analogues, modulation of insulin receptor isoform specificity and targeted delivery approaches. Attention is given to hepato-preferential, muscle-directed, brain-targeted and adipose-modulating strategies, highlighting their mechanistic basis, therapeutic potential and inherent limitations. While proof of principle has been established for several approaches, challenges remain in balancing tissue selectivity with whole-body metabolic control. Advances in protein design and delivery technologies may ultimately enable the development of next-generation insulin therapies that better mimic physiological insulin action and improve clinical outcomes in metabolic and neurodegenerative diseases.