Current insulin therapy only crudely mimics physiological secretion of insulin. Part of this difficulty is related to the hexameric structure of pharmacological preparations of insulin. This structure delays the absorption of insulin from the injection site, results in changes in the time to peak insulin action, and causes changes in its duration of action as a function of changing dosage. These changes occur with both regular and intermediate acting insulin. Insulin analogues, which are monomeric, will have a faster onset of action (more closely approximating endogenous insulin) and greater reproducibility of effect. Insulin analogues with low isoelectric points may provide more stable basal delivery as support to endogenous insulin production (i.e. monotherapy) or in conjunction with prandial insulins or oral agent therapy. The main advantages of these preparations in elderly diabetic patients may be a reduced risk of hypoglycaemia, improved predictability of response, and greater flexibility in more frail elderly patients, such as those with variable oral intake or compromised renal function.