Preclinical evidence and therapeutic perspectives on carnosine for the treatment of neurodegenerative disorders

Carnosine (β-alanyl-L-histidine) is an endogenous dipeptide widely distributed in mammalian tissues, especially skeletal and cardiac muscle cells, and, to a lesser extent, in the brain. While early interest in carnosine was given because of its role in muscle cell metabolism and athletic performance, it has more recently gained attention for its potential application in several chronic diseases. Specifically, brain aging and neurodegenerative disorders have received particular attention, as a marked reduction in carnosine levels has been described in these conditions. Carnosine exerts a wide range of biological activities, including antioxidant, anti-inflammatory, anti-glycation, metal-chelating, and neuroprotective properties. Mechanistically, it acts by inhibiting the production of advanced glycation end products (AGEs), buffering cellular pH, and regulating intracellular nitric oxide signaling and mitochondrial function. Its safety profile, the lack of toxicity, and significant side effects support its application for long-term therapeutic use. In this review, we aim to recapitulate and discuss the effects, dosages, and administration routes of carnosine in preclinical in vivo models, with a particular focus on neurodegenerative disorders where it has been shown to reduce oxidative stress, suppress neuroinflammation, modulate protein aggregation, and preserve cognitive function, all key features of neurodegeneration. Despite promising findings, there are gaps in the knowledge on how carnosine affects synaptic plasticity, neuronal remodeling, and other processes that play a central role in the pathophysiology of neurodegenerative disorders. Additionally, clinical translation remains challenging due to inconsistencies across in vivo studies in terms of dosage, treatment duration, routes of administration, and disease models, which affect reproducibility and cross-study comparability. Therefore, while carnosine emerges as a multifunctional and well-tolerated molecule, further research is needed to clarify its therapeutic relevance in human diseases. In this review, we also address future perspectives and key methodological challenges that must be overcome to effectively translate carnosine’s biological potential into clinical practice.