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Glucagon: 7 things you should know

Medically reviewed by Carmen Fookes, BPharm. Last updated on June 9, 2021.

1. How it works

  • Glucagon is identical to the glucagon produced by our bodies, which is a hormone that helps to increase blood sugar levels.
  • Glucagon is produced naturally in our bodies by alpha cells, found in the islet cells of the pancreas. It helps stimulate the conversion of stored glycogen in the liver into glucose. This is then released into the bloodstream. It also stimulates the liver to produce more glucose from amino acid molecules and reduces how much glucose the liver needs to function so that as much glucose as possible can be released into the bloodstream. Glucagon also relaxes the smooth muscle of the GI tract, slowing down digestion, and acts on adipose (fat) tissue to increase the breakdown of fat stores into the bloodstream. glucagon is naturally produced in the body when blood sugars become low. Synthetic glucagon given by injection helps to increase blood sugar (glucose) levels in those with severely low blood sugar levels (also called a hypoglycemic emergency) by releasing stored glucose from the liver.
  • Glucagon belongs to the class of medicines called glucose elevating agents.

2. Upsides

  • May be used to treat severe hypoglycemia (extremely low blood sugar levels) that may occur in adults or children with diabetes. If possible, severe hypoglycemia should be treated initially with intravenous glucose.
  • May be used as a diagnostic aid during radiologic examinations to temporarily inhibit movement of the gastrointestinal tract. Do not use in combination with anticholinergic agents due to the possibility of increased side effects. After the end of the diagnostic procedure, give oral carbohydrates to patients who have been fasting if not contraindicated by the diagnostic procedure.
  • Can be administered to people with suspected severe hypoglycemia who are unconscious or having a seizure.
  • May be given by subcutaneous, intramuscular, or intravenous injection.
  • There does not appear to be a risk associated with using glucagon during pregnancy; however, studies have indicated that there is a lack of transfer of pancreatic glucagon across the placenta during early gestation. In breastfeeding infants, glucagon is likely to be broken down in an infant's digestive tract and is unlikely to cause harm.
  • Reported to be safe and effective in children.
  • The dose of glucagon is 1mL (1mg) for everyone over 55 pounds [25kg] or 0.5mL (0.5mg) for everyone who weighs less than 55 pounds [25kg].
  • Glucagon is a generic.

3. Downsides

If you are between the ages of 18 and 60, take no other medication or have no other medical conditions, side effects you are more likely to experience include:

  • Nausea, vomiting, and transient tachycardia (fast heartbeat), and high blood pressure are the most common side effects reported. Vomiting was the most common side effect reported in children, followed by a headache. Allergic reactions have also been reported with glucagon preparations, including anaphylactic shock and a generalized rash.
  • A glucagon vial contains a dry powder that must be mixed with sterile water (supplied) before being administered as an injection. Ensure patients and their caregivers know how to prepare and administer glucagon before having to give it in an emergency.
  • People with type 1 diabetes may have less of a response to glucagon than those with type 2 diabetes.
  • Because glucagon depletes glycogen stores, administer supplemental carbohydrates to the patient as soon as he/she awakens and can swallow, especially children or adolescents. Medical evaluation is recommended for all patients who experience severe hypoglycemia.
  • If there is no response to glucagon within 15 minutes, administer a second dose of glucagon. After glucagon has been administered, call for emergency help right away. Turn the person on their side and put them in the recovery position if they are unconscious.
  • Glucagon is only effective in treating hypoglycemia if sufficient liver glycogen is present. Glucagon may not be effective in people who are malnourished, with adrenal insufficiency, or with longstanding hypoglycemia.
  • Should not be given to people with pheochromocytoma because glucagon may stimulate the release of catecholamines (hormones such as dopamine; norepinephrine and epinephrine) from the tumor. If a person has a sudden increase in blood pressure after glucagon administration, consider the possibility of previously undiagnosed pheochromocytoma and administer 5 to 10 mg of phentolamine mesylate.
  • Do not use in patients with insulinoma. In people with insulinoma, although glucagon may produce an initial increase in blood glucose, it may then directly or indirectly (through an initial rise in blood glucose) stimulate exaggerated insulin release from an insulinoma and cause hypoglycemia. If a person develops symptoms of hypoglycemia after a dose of glucagon, give oral or intravenous glucose.
  • Continuous glucagon infusion has been associated with necrolytic migratory erythema (NME), a skin rash characterized by scaly, pruritic erythematous plaques, bullae, and erosions. This resolved on discontinuation of glucagon, but treatment with corticosteroids was ineffective.
  • In people with cardiac disease, be careful using glucagon in endoscopic or radiographic procedures to inhibit gastrointestinal motility.
  • There is a lack of data about the use of glucagon during pregnancy and breastfeeding. Only use during pregnancy if clearly needed. It is not known if glucagon is excreted into human milk; however, glucagon is not active when taken orally because it is broken down by the gastrointestinal tract, and is unlikely to cause harm to a newborn.

Note: In general, seniors or children, people with certain medical conditions (such as liver or kidney problems, heart disease, diabetes, seizures) or people who take other medications are more at risk of developing a wider range of side effects. View complete list of side effects

4. Bottom Line

Glucagon is a synthetic hormone that may be used to treat severely low blood sugar levels (severe hypoglycemia) in adults and children with diabetes, or as a diagnostic aid during a radiologic examination. Family members and caregivers should recognize the signs of severe hypoglycemia and act quickly. Glucagon may be used when people are unconscious or having a seizure and works within 10 minutes. Trials report 100% of people respond within 30 minutes.

5. Tips

  • A glucagon kit contains a vial with a dry powder that must be mixed with sterile water before being administered as an injection. Make sure you understand the instructions for mixing and administering glucagon before you need to give it in an emergency.
  • Severely low blood sugar levels are an emergency and if you are caring for somebody with suspected hypoglycemia (low blood sugar levels) you should not leave them alone. If untreated, very low blood sugar levels can cause seizures, coma, or death.
  • Symptoms of very low blood sugar include confusion, coordination difficulties, difficulty eating or drinking due to the person being confused or uncooperative, unconsciousness, or seizures. Administer glucagon as soon as severely low blood sugar levels are recognized.
  • To administer a glucagon injection, first, open the Glucagon Emergency Kit for Low Blood Sugar and mix the glucagon powder vial and the prefilled syringe containing the diluent (sterile water). This must be done just before administration. The powder should dissolve to form a clear liquid. Do NOT use if you can see particles in the solution or if a gel has formed. With the needle still inserted into the vial carefully turn the vial and syringe upside down, then gently pull down the plunger of the syringe to draw up all of the liquid into the syringe. Draw up the correct dose of glucagon (see below).
  • The dose of glucagon for adults and children who weigh over 55 pounds (25kg) is 1mg (1ml) and for those who weigh less than 55 pounds (25kg) is 0.5mg (0.5ml).
  • Administer the injection into the upper outer arm, thigh, or buttocks. Gently pinch the skin to form a bump, then insert the needle into the person’s skin and push the plunger down until the syringe is empty. Once the syringe is empty pull the needle out of the skin.
  • After a glucagon injection put the person in the recovery position (roll them onto their side), and call for emergency help. Encourage the person to eat as soon as they can and can swallow safely. Initially give them a fast-acting source of sugar, such as juice, then a snack such as cheese and crackers or peanut butter. If a person does not respond within 15 minutes give them another dose of glucagon if available.
  • Throw away the used glucagon syringe and arrange for a replacement kit as soon as possible.
  • Tell your family, friends, and work colleagues that you have diabetes and explain what they should do if you develop severe hypoglycemia. Show them where you keep your glucagon kit and how to use it. Explain to them that hypoglycemia needs to be treated as quickly as possible because having low blood sugar levels for too long can cause seizures, coma, or death.
  • Try to avoid large fluctuations on a day-to-day basis in your diet, insulin, or exercise. This will help keep your blood sugar levels in a more stable range. Always carry sugar, candy, or another kind of readily absorbable carbohydrate with you to eat if you start to feel early symptoms of low blood sugar levels, such as dizziness, tiredness, or sweating.
  • Store your glucagon kit at room temperature 20C to 25C (68F to 77F). Do not keep in the refrigerator or freeze and keep in the original package to protect from light. Do not use it after the expiry date. Once mixed with the diluent, administer immediately unless the solution shows gel or particle formation. Discard any unused portion.
  • Glucagon make not be suitable for some people such as those with medical conditions such as kidney or pancreas disease, heart disease, glucagonomas (insulin-producing tumors), who are malnourished, or with chronic low blood sugar levels. It should only be used during pregnancy if clearly needed.

6. Response and effectiveness

  • Starts working within 10 minutes of injection, with peak levels being reached 20 to 30 minutes after IM or IV administration. Maximal concentrations are reached 30 to 45 minutes after SC injection.
  • One injection of glucagon given either IM or IV lasts 60 to 90 minutes.
  • In clinical trials, 100% of people with severe hypoglycemia treated with glucagon responded within 30 minutes.
  • Always followed up a dose with a fast-acting source of sugar (eg fruit juice, glucose gel) and a snack or small meal such as crackers with cheese or peanut butter because the effects of glucagon will start to wear off after at least 90 minutes. Seek emergency medical assistance immediately after administering glucagon.

7. Interactions

Medicines that interact with glucagon may either decrease its effect, affect how long it works for, increase side effects, or have less of an effect when taken with glucagon. An interaction between two medications does not always mean that you must stop taking one of the medications; however, sometimes it does. Speak to your doctor about how drug interactions should be managed.

Common medications that may interact with glucagon include:

  • anticholinergics, such as benztropine (increased gastrointestinal side effects)
  • beta-blockers, such as atenolol, propranolol, sotalol, or timolol (may cause a short-term increase in blood pressure and pulse)
  • indomethacin (may interfere with glucagon's ability to raise blood sugar levels and may cause hypoglycemia)
  • insulin (has the opposite effect to glucagon)
  • warfarin (may increase the anticoagulant effect).

Note that this list is not all-inclusive and includes only common medications that may interact with glucagon. You should refer to the prescribing information for glucagon for a complete list of interactions.


Glucagon. Updated 02/2021. Amphastar Pharmaceuticals, Inc.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use glucagon only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Copyright 1996-2022 Revision date: June 9, 2021.