and flexpen goes wherever i go. levemir is a long-acting insulin used to control high blood sugar in adults and children with diabetes. do not take if your blood sugar is too low. tell your healthcare provider about all medicines you take and all of your medical conditions, including if you are pregnant or breastfeeding. the most common side effect is low blood sugar. other possible side effects include reactions at the injection site. get medical help right away if you experience serious allergic reactions, such as body rash, trouble with breathing, fast heartbeat or sweating. ask your healthcare provider about levemir flexpen today. learn more about the different insulins available in flexpen at myflexpen.com. flexpen, insulin delivery that goes with you.