Treatment combining long-acting and short-acting insulins is essential for people with type 1 diabetes, but may become also compulsory in other forms of diabetes in case of insulinopenia. The purpose of short-acting insulins is to mimic physiological insulin secretion in response to carbohydrate intake at meals. There is a delay between the injection and its action, sometimes limiting their use and effectiveness. Ultra-rapid insulins have been developed to more closely approximate the expected insulin response to a meal, through faster absorption. They do not improve diabetes control but allow more flexibility with mealtime injections. These new analogues are also an attractive alternative for use in insulin pumps.