The U.S. Food and Drug Administration (FDA) has approved Eli Lilly and Company's Humulin® R U-500 KwikPen®(insulin human injection) 500 units/mL, a pre-filled device containing Humulin R U-500, a highly concentrated formulation of insulin. Humulin R U-500 is the only FDA-approved insulin that is five-times more concentrated than standard U-100 insulin. This insulin is used to treat high blood sugar in people with type 1 and type 2 diabetes who need more than 200 units of insulin per day. The safety and efficacy of Humulin R U-500 used in combination with other insulins or delivered by an insulin infusion pump has not been determined.