Glucagon is a hormone that your pancreas makes to help regulate your blood glucose (sugar) levels. Glucagon increases your blood sugar level and prevents it from dropping too low, whereas insulin, another hormone, decreases blood sugar levels.

What is glucagon?

Glucagon is a natural hormone your body makes that works with other hormones and bodily functions to control glucose (sugar) levels in your blood. Glucagon prevents your blood sugar from dropping too low. The alpha cells in your pancreas make glucagon and release it in response to a drop in blood sugar, prolonged fasting, exercise and protein-rich meals.

Hormones are chemicals that coordinate different functions in your body by carrying messages through your blood to your organs, skin, muscles and other tissues. These signals tell your body what to do and when to do it.

Your pancreas is a glandular organ in your abdomen that secretes several enzymes to aid in digestion and several hormones, including glucagon and insulin. It’s surrounded by your stomach, intestines and other organs.

Glucose is the main sugar found in your blood. You get glucose from carbohydrates in the food you eat. This sugar is an important source of energy and provides nutrients to your body's organs, muscles and nervous system. Glucose is very important because it’s the primary source of energy for your brain.

Your body normally has a complex system to make sure your blood sugar is at optimum levels. If you have too much or too little glucose in your blood, it can cause certain symptoms and complications.

Glucagon injections and nasal sprays

There’s also a synthetic form of glucagon that can be administered as an injection or nasal powder (dry nasal spray). People with Type 1 diabetes primarily use this form of glucagon in emergency situations when they have very low blood sugar. Synthetic glucagon triggers your liver to release stored glucose, which then raises blood sugar.


Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy

What is the function of glucagon?

Your body normally carefully regulates your blood glucose (sugar) primarily with the hormones glucagon and insulin. When your blood glucose levels trend lower or fall too low (hypoglycemia), your pancreas releases more glucagon. Glucagon helps blood glucose levels rise back up in multiple ways, including:

  • Glucagon triggers your liver to convert stored glucose (glycogen) into a usable form and then release it into your bloodstream. This process is called glycogenolysis.
  • Glucagon can also prevent your liver from taking in and storing glucose so that more glucose stays in your blood.
  • Glucagon helps your body make glucose from other sources, such as amino acids.

If your blood glucose levels trend higher, your pancreas releases insulin to bring it back into range.

What is the difference between glucagon and insulin?

Glucagon and insulin are both important hormones that play essential roles in regulating your blood glucose (sugar). Both hormones come from your pancreas — alpha cells in your pancreas make and release glucagon, and beta cells in your pancreas make and release insulin.

The difference is in how these hormones contribute to blood sugar regulation. Glucagon increases blood sugar levels, whereas insulin decreases blood sugar levels. If your pancreas doesn’t make enough insulin or your body doesn’t use it properly, you can have high blood sugar (hyperglycemia), which leads to diabetes.


What is the difference between glucagon and glycogen?

Glucagon and glycogen are not the same. Glycogen is a stored form of glucose (sugar). Your body primarily stores glycogen in your liver and muscles.

Glucagon is a hormone that triggers liver glycogen to convert back into glucose and to enter your bloodstream so that your body can use it for energy.

What tests can check glucagon levels?

Healthcare providers don’t typically order glucagon level tests for people with diabetes, but they may order the test to help diagnose some rare endocrine conditions.

Your provider may order a glucagon blood test to measure your glucagon levels if you’re having certain symptoms. During the test, a provider will draw a blood sample from your vein using a needle. They will then send it to a lab for testing.


What are normal glucagon levels?

Normal glucagon value ranges can vary from lab to lab and depending on the duration of fasting and blood glucose level(s). Always compare your results to the reference range given on your blood lab report, and talk to your healthcare provider if you have questions.

In general, the normal range of glucagon levels in your blood is 50 to 100 picograms per milliliter (pg/mL). A picogram is one-trillionth of a gram.

What conditions are related to issues with glucagon function?

People with diabetes can develop an inability to release enough glucagon in response to decreasing blood glucose levels. Because of this, they’re more likely to develop frequent low or severely low blood sugars if they take medication that could cause low blood sugars — especially synthetic insulin and medications in the class of sulfonylurea.

People with Type 2 diabetes may have glucagon levels that are relatively higher than what would be considered normal based on blood glucose levels. This can contribute to higher blood sugars.

Glucagon production issues outside diabetes are uncommon, and some are rare. The following conditions can affect or be affected by your glucagon function:

  • Pancreatitis: People who develop inflammation of the pancreas (pancreatitis) may experience some complications. One of these is damage to the cells that make glucagon and insulin. A lack of insulin can lead to diabetes. If you develop diabetes from pancreatitis and take synthetic insulin for treatment, you’re at a higher risk of developing low blood sugars due to your pancreas’s inability to make and release enough glucagon.
  • Glucagonoma: This is a very rare tumor of the pancreas that releases excess amounts of glucagon. It causes certain symptoms, including high blood sugar, a skin rash called necrotizing migratory erythema, weight loss, mild diabetes, anemia, an inflamed and sore mouth (stomatitis) and a swollen tongue (glossitis).
  • Multiple endocrine neoplasia: This is a rare genetic condition in which you have tumors in more than one of your endocrine system glands, which includes your pancreas. Since you can develop a tumor in your pancreas, this condition could potentially affect your glucagon levels.
  • Cirrhosis of the liver: Cirrhosis is a late-stage liver disease in which your body replaces healthy liver tissue with scar tissue. Scar tissue keeps your liver from working properly. Since your body stores a lot of glucose in your liver and glucagon works to release that stored liver glucose, cirrhosis could prevent your body’s glucagon from working properly. This may apply to other rare liver conditions as well.
  • Pancreatectomy side effect: People who need to have their pancreas partially or fully removed (pancreatectomy), will lose some or all of the cells that release glucagon and insulin, which can affect how your body is able to use glucagon.

What are the symptoms of glucagon-related conditions?

Depending on the situation and condition, you can experience low and/or high blood sugar from abnormal glucagon levels.

Symptoms of low blood sugar (hypoglycemia)

The signs and symptoms of low blood sugar include:

  • Shaking or trembling.
  • Sweating and chills.
  • Dizziness or lightheadedness.
  • Faster heart rate.
  • Hunger.
  • Confusion or trouble concentrating.
  • Nervousness or irritability.
  • Pale skin.
  • Weakness.
  • Tingling or numbness in your face or mouth.

If you’re experiencing these symptoms, it’s important to eat food with carbohydrates/sugar to treat it and bring your blood sugar levels up. If you experience these symptoms often, contact your healthcare provider.

Symptoms of high blood sugar (hyperglycemia)

While high blood sugar levels are most commonly caused by an issue with not having enough insulin and not an isolated glucagon issue, it’s possible to have elevated blood sugar levels from rare glucagon issues. Early signs and symptoms of high blood sugar include:

Additional symptoms include:

If you’re experiencing these symptoms, it’s important to see your healthcare provider.

When should I see a healthcare provider about my glucagon levels?

If you have diabetes and are experiencing frequent episodes of low or high blood sugar, it’s important to contact your healthcare provider. Glucagon levels are usually not measured or monitored in people with diabetes, but your provider may need to adjust your medication management (and sometimes lifestyle management) to minimize both low and high blood sugar episodes.

While other glucagon issues are rare, if you’re having symptoms, it’s essential to figure out the cause. Reach out to your healthcare provider.

A note from Cleveland Clinic

Glucagon is a very important hormone that helps regulate your blood sugar levels. Even though non-diabetes-related issues with your body’s ability to make and use glucagon are rare, it’s important to see your healthcare provider if you’re experiencing symptoms of low or high blood sugar. They can run some tests to see if the cause is an issue with your body’s glucagon or something else.

It’s also important to see your provider regularly if you have diabetes, especially if you frequently experience low and/or high blood sugar. If you treat your diabetes with insulin, make sure you have emergency glucagon on hand in case you experience a severe low blood sugar episode.

Medically Reviewed

Last reviewed on 01/03/2022.

Learn more about our editorial process.

Appointments 216.444.6568