This study explores transdermal insulin patch technology as a possible alternative to conventional subcutaneous insulin injections in managing diabetes mellitus. A quasi-experimental design was utilized in this study, comparing the efficacy, safety, patient satisfaction, and adherence of insulin patches with subcutaneous insulin injections. A total of 150 adults, 75 in each group, with a medical diagnosis of either Type 1 or Type 2 diabetes mellitus, were recruited from diabetes management clinics. Glycemic parameters were measured pre- and post-intervention for six months on both groups, including HbA1c and glucose levels while fasting. Results indicated that both the treatment groups revealed significant reductions in HbA1c and fasting glucose. The insulin patch group had an even more pronounced reduction in HbA1c and glucose levels. The insulin patch was well-tolerated, with only 12% of participants experiencing mild skin irritation. Patient satisfaction was significantly higher in the experimental group, with 88% rating the insulin patch as "very convenient" compared to 46% in the control group.