The negative consequencies of diabetes treatment are traditionally regarded as caused by a disastrous treatment rather than adverse events of the insulin preparations. However, hypoglycemia, changes at the injection site (lipatrophy, lipoma), insulin allergy, obesity and increased risk of certain forms of cancer can easily be regarded as adverse events of the drug, and needle -phobia, psychological problems, increased risk of suicide are adverse events related to insulin and its administration. Also macroongiopathy and even microangiopathy to some extent can be regarded as adverse events as the most crucial part of the treatment of Type 1 diabetes is the insulin treatment. There is still room for improvments of insulin as a drug. We need insulins with more predictable absorption and kinetics, leading to more stable near-normal blood glucose, less risk of hypoglycemia, less effect in periphery and more effect on the liver, and less risk of vascular complications, obesity, cancer.