Glucagon test (blood) Biomarker Testing
A glucagon test measures a pancreas hormone that raises blood sugar and helps evaluate unexplained hypoglycemia; order through Vitals Vault with Quest labs.
With Vitals Vault, you have access to a comprehensive range of biomarker tests.
Glucagon is a hormone made by your pancreas that helps keep your blood sugar from dropping too low. When glucose falls, glucagon signals your liver to release stored sugar into the bloodstream.
A glucagon blood test is not a routine wellness lab for most people. It is usually ordered when you have episodes of low blood sugar (hypoglycemia) that are unexplained, severe, or happening while you are fasting.
Because glucagon is tightly linked to glucose and insulin, the number is most useful when it is interpreted alongside other labs drawn at the same time and in the right clinical situation. Your result can support clinician-directed care, but it cannot diagnose a condition by itself.
Do I need a Glucagon test?
You may benefit from a glucagon test if you have repeated or severe symptoms that could reflect hypoglycemia, especially when they occur during fasting or overnight. These symptoms can include shakiness, sweating, confusion, blurred vision, fainting, or seizures. If you have documented low glucose readings, a glucagon level can help your clinician understand whether your pancreas and liver are responding appropriately.
This test is also considered when there is concern for rare hormone-secreting tumors of the pancreas (such as a glucagonoma) or certain genetic and metabolic conditions that affect glucose regulation. In those cases, glucagon is typically part of a broader workup rather than a stand-alone answer.
If your main concern is insulin resistance, prediabetes, or diabetes management, glucagon may not be the first test to start with. More common starting points include fasting glucose, HbA1c, and sometimes insulin or C-peptide, and then glucagon is added if your pattern suggests an abnormal counter-regulatory response.
If you are currently having frequent hypoglycemia, are pregnant, have liver or kidney disease, or use glucose-lowering medications, it is worth discussing timing and companion labs with your clinician so the result is interpretable.
Glucagon is measured from a blood sample in a CLIA-certified laboratory; results should be interpreted with your symptoms and same-time glucose/insulin labs and are not a stand-alone diagnosis.
Lab testing
Order a glucagon test through Vitals Vault and choose a nearby Quest draw location.
Schedule online, results typically within about a week
Clear reporting and optional clinician context
HSA/FSA eligible where applicable
Get this test with Vitals Vault
Vitals Vault lets you order a glucagon blood test without needing a separate lab visit referral, and you can choose a nearby Quest draw location for your sample collection.
Because glucagon is sensitive to context, you will get the most value when you pair the result with the right companion tests and a clear plan for what you will do next. PocketMD can help you review your result in plain language, generate questions to bring to your clinician, and decide whether retesting or broader metabolic testing makes sense.
If you are tracking symptoms over time, Vitals Vault makes it easier to repeat testing in a consistent way so you can compare trends rather than guessing from a single snapshot.
- Order online and draw at a local Quest location
- PocketMD helps you interpret results and plan follow-up questions
- Easy reordering when you need a repeat or companion labs
Key benefits of Glucagon testing
- Helps clarify whether your body is mounting an appropriate “raise blood sugar” response during suspected hypoglycemia.
- Adds context to insulin and glucose results when symptoms do not match routine diabetes labs.
- Supports a structured workup for fasting or overnight low blood sugar episodes.
- Can be a useful data point when evaluating rare pancreatic hormone-secreting tumors in the right clinical setting.
- Helps your clinician distinguish between different causes of hypoglycemia when drawn with same-time glucose, insulin, and C-peptide.
- Provides a baseline you can compare against if you retest after medication changes, illness, or significant weight change.
- Pairs well with PocketMD guidance so you can translate a complex hormone result into practical next steps.
What is Glucagon?
Glucagon is a peptide hormone produced by alpha cells in your pancreas. Its main job is to prevent your blood sugar from dropping too low, especially between meals and overnight.
When your glucose level falls, glucagon signals your liver to break down stored glycogen and to make new glucose (gluconeogenesis). This raises blood sugar and helps supply fuel to your brain and muscles. Glucagon generally works in the opposite direction of insulin, which lowers blood sugar by helping cells take up glucose.
Because glucagon changes quickly based on fasting, stress, exercise, illness, and medications, a single result is most meaningful when you know the circumstances of the blood draw. Many clinicians interpret glucagon as part of a “critical sample” collected during a documented hypoglycemic episode, along with glucose and other hormones.
A glucagon blood test measures the amount of glucagon circulating in your blood at the time of collection. It does not directly measure how sensitive your liver is to glucagon’s signal, and it does not replace glucose monitoring when you are having symptoms.
How glucagon fits into blood sugar regulation
Your blood sugar is regulated by a balance of hormones. Insulin lowers glucose after you eat, while glucagon raises glucose when you are fasting. Other hormones, including cortisol, growth hormone, and epinephrine, also help protect you from hypoglycemia, which is why a full evaluation may look beyond glucagon alone.
Why timing matters for this test
Glucagon can be higher during fasting and lower after eating, but the pattern varies by person. If your blood was drawn when you were not fasting, when you were acutely stressed, or long after symptoms resolved, the number may not reflect what was happening during the episode you are trying to explain.
What do my Glucagon results mean?
Low glucagon levels
A low glucagon result can mean your pancreas is not releasing enough glucagon when your body needs it, which may contribute to hypoglycemia in some situations. It can also be seen if the sample was drawn after eating, after glucose was given, or when your blood sugar was not actually low at the time. In people with long-standing diabetes who have recurrent hypoglycemia, impaired glucagon response can be part of the reason lows become harder to recognize and correct. Your clinician will usually interpret a low value alongside same-time glucose and other counter-regulatory hormones.
In-range (expected) glucagon levels
An in-range result suggests your glucagon level is within the laboratory’s expected range for the draw conditions, but it does not automatically rule out a problem. If you were not hypoglycemic at the time of collection, a normal glucagon level may simply reflect a normal baseline. If the test was drawn during a documented low glucose episode, an “appropriate” glucagon response is typically one that rises in a way that matches the severity of the low. The key question is whether the glucagon level makes sense for your glucose level and symptoms.
High glucagon levels
A high glucagon result can occur when your body is trying to raise blood sugar during fasting, illness, or physiologic stress. Persistently elevated glucagon may also be seen in certain metabolic states, including poorly controlled diabetes, and in some liver or kidney conditions that affect hormone clearance. In rare cases, markedly high glucagon can raise concern for a glucagon-secreting tumor, especially if you also have suggestive symptoms such as unexplained weight loss, a characteristic rash, or new/worsening diabetes. Because elevations are not specific, follow-up usually focuses on confirming the pattern and checking related markers.
Factors that influence glucagon
Fasting status, recent carbohydrate intake, and how long it has been since symptoms occurred can all shift glucagon levels. Acute stress, infection, strenuous exercise, and alcohol use can change glucose regulation and indirectly affect glucagon. Medications matter too, including insulin and other glucose-lowering drugs; your clinician may also consider whether you use agents that affect gut hormones or appetite. Sample handling can be important for peptide hormones, so repeating the test under standardized conditions may be recommended when the result does not match your clinical picture.
What’s included
- Glucagon
Frequently Asked Questions
Do I need to fast for a glucagon blood test?
Often, yes, because fasting helps standardize the conditions and makes the result easier to interpret. However, the “right” timing depends on why you are testing. If your clinician is evaluating true hypoglycemia, the most informative sample may be drawn during symptoms with a confirmed low glucose, which may not follow a planned fasting schedule.
What is a normal glucagon level?
“Normal” depends on the lab method and the draw conditions (fasting vs non-fasting), so you should use the reference interval printed on your report. More importantly, glucagon is usually interpreted relative to your glucose at the same time. A value that is technically in range may still be considered inappropriately low if your glucose was very low.
What does high glucagon mean?
High glucagon can be a normal response to fasting or stress, but it can also be associated with metabolic dysregulation such as poorly controlled diabetes. Less commonly, very high levels can be seen with glucagon-secreting tumors, especially when paired with specific symptoms. Because many common situations can raise glucagon, follow-up typically includes repeat testing and companion labs rather than conclusions from one result.
Can glucagon explain my hypoglycemia symptoms?
It can be part of the explanation, but it is rarely the whole story. Hypoglycemia evaluation usually depends on documenting low glucose and then checking insulin, C-peptide, and sometimes beta-hydroxybutyrate and cortisol at the same time. Glucagon adds information about your counter-regulatory response, which can help narrow causes when interpreted in context.
How is a glucagon blood test different from a glucagon injection kit?
A glucagon blood test measures your hormone level in the lab. A glucagon injection kit is a medication used to treat severe hypoglycemia by raising blood sugar. The lab test does not treat hypoglycemia, and the medication does not tell you what your baseline glucagon level is.
When should I retest glucagon?
Retesting is most useful when the first result was drawn under unclear conditions, when your symptoms change, or when you and your clinician are trying to confirm a pattern. Many people get the clearest answers when glucagon is drawn with a same-time glucose sample under a standardized fasting plan or during a documented episode. PocketMD can help you decide what “standardized” should mean for your situation before you reorder.