GlucaGen® contains an injection of glucagon, and works by triggering the liver to release stored sugar, raising blood sugar levels. It is injected under the skin, similar to how insulin is injected. Do not use GlucaGen® if you have a tumor in the gland on top of your kidneys (adrenal gland) called a pheochromocytoma, you have a tumor in your pancreas called an insulinoma, you are allergic to glucagon or any of the ingredients in GlucaGen®, or you have a tumor in your pancreas called a glucagonoma because it could cause low blood sugar when used for your radiology tests.