Several decades of intensive research into antidiabetic therapeutics have yielded an expansive, mechanism-driven pharmacopeia. Yet, the clinical endpoint for these diverse agents remains singular and superficial: the reduction in glycated hemoglobin (HbA1c). By focusing primarily on downstream glucose lowering, current therapeutic paradigms treat the symptom rather than the etiology. This approach persists despite definitive consensus that the foundational pathology of type 2 diabetes is much more complex which paves the way to insulin resistance, not merely the spillover of glucose into the bloodstream. This systemic misalignment raises a critical question for the scientific community: are we collectively “agreeing to disagree” on a biological fact or a clinical myth? The Myth is that ‘Persistent hyperglycemia’ is the disease itself, but the fact is: hyperglycemia is a late-stage biomarker of systemic insulin resistance. By managing the biomarker rather than the root cause, clinical medicine has normalized an incomplete treatment model. This review aims to deliberately provoke a shift in rational thinking. We challenge the comfortable status quo of accepting hyperglycemia as the primary definition of diabetes. True therapeutic innovation requires moving past this consensus of convenience. We must reorient basic and clinical science toward reversing the cellular mechanisms of insulin resistance itself, rather than settling for the cosmetic management of blood glucose levels. Rather than merely recounting established therapeutic mechanisms, this review systematically bridges classical antidiabetic pharmacology with the specific pharmacogenomic determinants likely driving hyperglycemia and phenotypic insulin resistance. Mechanisms of action and pharmacogenomic perspectives of α-glucosidase inhibitors, Sulfonylureas, SGLT2 inhibitors, GLP-1 agonists, Meglitinides, Insulins, Metformin, Thiazolidinediones, and DPP4 inhibitors are discussed in this review. In conclusion, mapping the pharmacogenetic landscape of antidiabetic therapies reveals how distinct genetic variations likely dictate drug metabolism and insulin receptor kinetics. Decoding these patient-specific mechanisms is essential to reverse tissue-specific insulin resistance and transition from empirical prescribing to precise, genotype-directed diabetes management.