The prevalence of age-related dry eye disease (DED) is rapidly increasing with global aging, and progressive lacrimal gland (LG) dysfunction represents a central pathogenic mechanism for which targeted therapies remain limited. Semaglutide (Sema), a glucagon-like peptide-1 receptor agonist widely used in metabolic diseases, has recently shown anti-aging effects in multiple tissues, yet its effects on LG aging and age-related DED have not been defined. Here, using a naturally aged mouse model, we show that long-term Sema treatment significantly alleviates DED related phenotypes and preserves LG structural integrity. High-throughput single-cell transcriptomic analyses revealed that LG aging was characterized by extensive remodeling of cellular composition, loss of acinar cells, expansion of fibroblasts and immune populations, and enhanced intercellular communication, all of which were broadly attenuated by Sema treatment. SenMayo-based profiling demonstrated widespread accumulation of senescent cells across epithelial, stromal, and immune compartments, accompanied by activation of stress-, inflammatory-, and apoptotic transcriptional programs. Sema markedly reduced senescent cell burden and senescence-associated transcriptional activation, consistent with decreased SA-β-gal activity, p21 expression, and SASP-related factors in LGs, and reduced systemic inflammatory cytokines. Mechanistically, Sema exerted cell-type-specific effects by alleviating oxidative stress and enhancing stress adaptation in acinar cells, suppressing extracellular matrix remodeling and pro-fibrotic programs in fibroblasts, and dampening pro-inflammatory and chemotactic activation in macrophages. Together, these findings demonstrate that Sema mitigates age-related LG dysfunction and DED through coordinated attenuation of senescence-associated pathological programs, supporting cellular senescence as a pharmacologically tractable mechanism and highlighting Sema as a potential therapeutic strategy for age-related DED.
