Carnosine, a naturally occurring dipeptide present in an omnivorous diet, has been shown to ameliorate the development of metabolic syndrome, type 2 diabetes and early- and advanced-stage diabetic nephropathy (Albrecht et al. 2017) in different rodent models. The physiological mechanisms of the protection by carnosine is presumably related to its anti-lipidemic, anti-hyperglycemic and anti-glycation actions. As anserine, its methylated analogue, is more bio-available in humans upon supplementation (Everaert et al. 2018) without affecting its functionality, it was now aimed to investigate the effect of oral supplementation with anserine on the development of severe diabetes and advanced diabetic nephropathy in BTBR ob/ob mice. Male and female BTBR ob/ob mice were either supplemented with 4mM carnosine or anserine in drinking water for 18 weeks and compared with non-supplemented BTBR ob/ob and wt/wt mice. Tissue carnosine and anserine levels were determined with HPLC and metabolic markers were determined in clinical lab of University Hospital UZ Ghent. Gastrocnemius carnosine and anserine levels were lower in male ob/ob vs. wt/wt mice, but were not affected by supplementation. Kidney carnosine and anserine levels were not different between ob/ob and wt/wt mice, but anserine levels were significantly higher in anserine-treated mice compared to non-treated ob/ob mice. The evolution of fasting blood glucose, fructosamine, triglycerides and cholesterol was not affected by the supplementation regimen. The area of the glomerular tuft and whole glomerulus was bigger in ob/ob vs. wt/wt mice, but not affected by supplementation. Based on the currently measured markers, it is suggested that chronic oral anserine supplementation is not able to attenuate the development of diabetes or diabetic nephropathy in the severe model of BTBR ob/ob mice. Further research will have to elucidate whether anserine can attenuate milder forms of metabolic syndrome or type 2 diabetes.