Effect of an 'implementation intention' intervention on adherence to oral anti-diabetic medication in Brazilians with type 2 diabetes.

•Inadequate oral antidiabetic taking may contribute to poor glycemic control.•Diabetes-related distress relate to inappropriate medication adherence.•Behavioral strategies has promoted an improvement in antidiabetic taking.•An improvement in antidiabetic taking has influenced the glycemic control.•An improvement in antidiabetic taking has promoted decrease diabetes-related distress.