STORAGE: Insulin can be stored at room temperature for about three weeks. Unopened vials may be stored in the refrigerator for longer periods. Never freeze insulin because this destroys the insulin crystals.
INSULIN DELIVERY: Syringes are being used less and less for administering insulin. Instead, cartridges with a "Pen"-type delivery device are now available. The pen is convenient to carry and, for some people, easier to use than a conventional syringe; however, it still involves an injection. Nevertheless, a pen has a finer needle, which many people prefer.
SITE OF INJECTION: The best sites for routine insulin administration are the areas of the body with fat under the skin. These include the back of the arm, the front of the thigh, the buttocks and the abdomen. In people on relatively intensive insulin regimens (three to four shots daily), daytime insulin should be injected into the abdomen for more reliable absorption. Intermittent injections in a limb that is sometimes exercised can result in erratic absorption of insulin and blood sugars that seem hard to control. Other factors that affect insulin absorption include the type of insulin, the dose, depth of injection, injection technique, location of injection, exercise, temperature, and local blood flow.
ROTATION OF INJECTION: It has been previously recommended that individuals should rotate the site of injection to avoid skin and fat abnormalities at those sites. This was more a problem with beef/pork insulin, but is now only rarely encountered with human insulin. Nevertheless, varying the site of injection is still recommended.
INHALED INSULIN: Clinical studies are now being done on inhaled insulin. This delivery method will almost certainly be available in the near future, at least for short-acting insulin.