Since 1921, the benefits achieved by insulin therapy research have been constant. However, the fear of a hypoglycemia incidence and rigid time schedules of insulin therapy still interfere with treatment adherence, which is essential to achieve optimal glycemic control and minimize complications in diabetic patients. The possibility of using an ultra long- acting insulin analogue (degludec), which has an extensive and predictable pharmacokinetic profile over 24 hours, is analyzed in this context. Clinical trials have shown that this ultra long-acting insulin analogue administered in a flexible dosage treatment, reached a good glycaemic control with no increase on hypoglycemia risk. Although to follow a predefined plan in clinical practice is recommended, the possibility of flexibility in day to day dosage timing of this specific insulin analogue on requirement, could improve adherence in patients with a non-predictable and active social life and workday.