Aim: This study aimed to evaluate the biochemical alterations and pharmacological treatment outcomes in patients with Type 2 Diabetes Mellitus (DM), focusing on glycemic control, lipid profiles, renal and liver function, and medication adherence. Materials and Methods: This was an observational, prospective cohort study conducted over 12 months, involving 100 adult patients with Type 2 DM. Participants were recruited from a tertiary care hospital and followed at three-month intervals. Biochemical parameters, including fasting plasma glucose (FPG), glycated hemoglobin (HbA1c), lipid profiles, renal and liver function markers, and medication adherence using the Morisky Medication Adherence Scale (MMAS-8), were assessed at baseline and follow-ups. Pharmacological data, adverse drug reactions (ADRs), and treatment outcomes were analyzed using appropriate statistical methods. Results: At baseline, the mean age was 54.6 ± 9.4 years, with a nearly balanced gender distribution. HbA1c improved significantly from 8.9% to 7.2% (p < 0.001), and FPG decreased from 156.3 mg/dL to 122.5 mg/dL (p < 0.001) over 12 months. Lipid parameters showed marked improvement, with total cholesterol reducing from 215.4 mg/dL to 178.2 mg/dL (p < 0.001) and HDL increasing from 44.5 mg/dL to 50.6 mg/dL (p < 0.001). Renal and liver function parameters, including serum creatinine and ALT, improved significantly. Medication adherence increased, with high adherence rising from 45% to 58% (p < 0.001). ADRs declined from 20% to 11% over the study period. Conclusion: Biochemical monitoring and pharmacological optimization led to significant improvements in glycemic control, lipid profiles, organ function, and medication adherence in Type 2 DM patients. A patient-centered approach integrating biochemical assessments and individualized therapy is crucial for improving long-term outcomes.