Protein glycation inhibition is important to prevent secondary complications in diabetes mellitus. p-Cymene, a monoterpene commonly found in Cuminum cyminum was investigated in vivo and in vitro using aminoguanidine as a positive control. Streptozotocin induced diabetic rats were treated with 20mg cymene kg−1 body weight for 60days. Cymene treatment improved HbA1c compared with diabetic control and serum fructosamine levels were normalized. Nephropathic parameters like albumin excretion rate, serum creatinine and creatinine clearance rate were improved. The cymene treatment improved collagen solubility profile. In the in vitro studies cymene inhibited total AGEs fluorescence and pentosidine by 56.6% and 57%, respectively at 100μM concentration which was comparable with aminoguanidine (2mM) concentration. Glycation specific decline in BSA α-helix content (from 63.8% to 43.3%) and increase in β-sheet (from 3.7% to 17.4%) was prevented by cymene in vitro, implying its stabilization effect. Electrophoretic mobility of glycated BSA was increased as against cymene treated BSA samples. The results suggest that cymene could have therapeutic potential in the prevention of glycation mediated diabetic complications.