Despite the mass prevalence and usage, the synthetic drugs accompany various side effects which include hypoglycemia (for sulphonylureas, glinides), weight gain (for sulphonylureas, thiazolidinediones), cardiovascular risk (for sulphonylureas, thiazolidinediones), pancreatitis (for DPP-4 inhibitors, GLP-1 agonists), hepatitis (for thiazolidinediones, DPP-4 inhibitors), cancer risk (for DPP-4 inhibitors, GLP-1 agonists), gastrointestinal effects (for biguanides, GLP-1 agonists), lactic acidosis (for biguanides) (285). This evidence concerns the gene GCG and lactic acidosis.