Background: Adolescents with type 1 diabetes (T1D) often struggle with maintaining optimal self-care and glycemic control. Peer education, leveraging support from individuals with similar experiences, is a promising strategy for improving health behaviors in chronic conditions.

Objectives: This study aimed to evaluate the effectiveness of a structured peer education program on self-care behaviors and glycated hemoglobin (HbA1c) levels in adolescents with T1D.

Methods: In a quasi-experimental clinical trial, 62 adolescents (aged 12-18 years) with T1D and baseline HbA1c >7.5% were recruited from a single center (Ali Asghar Hospital, Zahedan, Iran) in 2023. Participants were randomized into an intervention group (receiving a 12-week program of four 90-minute peer-led educational sessions) and a control group (receiving routine care). Outcomes were measured at baseline and 12 weeks using the validated Persian version of the Summary of Diabetes Self-Care Activities (SDSCA) questionnaire and HbA1c tests. Data were analyzed using IBM SPSS Statistics (version 26) .

Results: All participants completed the study. The intervention group showed a significant improvement in self-care scores (from 65.7 ± 9.9 to 79.2 ± 11.0, p < 0.001) and a significant reduction in HbA1c levels (from 9.4 ± 1.3% to 8.1 ± 0.9%, p < 0.001). No significant changes were observed in the control group for either outcome.

Conclusions: A structured peer education program significantly improved self-care behaviors and glycemic control in adolescents with T1D within this trial context, suggesting it may be a valuable adjunct to conventional care. However, the findings should be interpreted considering the study's limitations, including its single-center design, relatively small sample size, reliance on self-reported measures for self-care, and lack of long-term follow-up.