Type 2 Diabetes Mellitus (T2DM) presents a significant public health burden in Kerala, India, where oxidative stress plays a pivotal role in pathophysiology. This prospective interventional observational study aimed to evaluate the effect of fresh Amla (Phyllanthus Emblica) juice supplementation on Glycated Haemoglobin (HbA1c) levels over a six-month period. The study was conducted at a Government Health Center in Kerala involving 156 patients with diagnosed T2DM (>5 years), baseline HbA1c between 7–9%, and strictly defined criteria excluding smokers and alcohol consumers to isolate the intervention's effect. Participants received daily supplementation of fresh Amla juice (equivalent to four fruits) for six months alongside stable standard pharmacological management. Anthropometric and biochemical parameters were assessed at baseline and six months. The study cohort demonstrated high compliance with the intervention. The mean baseline HbA1c was 8.12 ± 0.54%, decreasing to 7.47 ± 0.48% post-intervention, representing a statistically significant mean reduction of 8.0% from baseline (p < 0.05). No significant adverse events were reported. Adjunctive supplementation with fresh Amla juice resulted in significant glycemic improvement in non-smokers and non-alcoholics, supporting the integration of dietary antioxidants in diabetic care protocols.