Disclaimer: This article is for informational purposes only and does not constitute medical advice. It is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of a physician or other qualified health provider with any questions you may have regarding a medical condition.
Overview
Mounjaro is a brand name for tirzepatide, a once-weekly injection made by Eli Lilly Canada. Health Canada has authorized it for type 2 diabetes in adults and in children aged 10 and older. It is used together with diet and exercise to improve blood sugar control.
Mounjaro is not authorized in Canada for weight management. Zepbound contains the same medicine, tirzepatide, and is the product authorized for chronic weight management.
Mounjaro needs a prescription. BC residents can speak with a BC-licensed doctor by phone through Avee Health to ask whether it is appropriate for them. The doctor decides based on your health history. A prescription is not guaranteed.
In Canada, Mounjaro is authorized to improve blood sugar control, along with diet and exercise, in:
- Adults with type 2 diabetes. It can be used on its own when metformin is not suitable, or together with metformin, metformin and a sulfonylurea, metformin and an SGLT2 inhibitor, or basal insulin with or without metformin.
- Children and teens aged 10 to under 18 with type 2 diabetes, together with metformin, or with basal insulin with or without metformin.
Mounjaro is not a substitute for insulin. It is not for type 1 diabetes or diabetic ketoacidosis, and it is not authorized for weight management.
Tirzepatide
GIP and GLP-1 receptor agonist
diabetes
Prescription required
Available
How Mounjaro Works
Tirzepatide acts on two hormone receptors, GIP and GLP-1. Your gut releases both hormones after you eat. In people with type 2 diabetes it:
- Helps the pancreas release insulin when blood sugar is high
- Lowers glucagon, a hormone that raises blood sugar
- Slows how quickly the stomach empties, so sugar enters the blood more slowly after meals
Tirzepatide stays in the body for several days, which is why Mounjaro is injected once a week.
Dosage Instructions of Mounjaro
Your doctor sets your dose. The usual schedule in the Canadian product monograph is:
- Start: 2.5 mg once weekly for 4 weeks. This is a starting dose to help the body adjust, not a dose for blood sugar control.
- Then: 5 mg once weekly.
- If more blood sugar control is needed: the dose can go up in 2.5 mg steps, after at least 4 weeks on the current dose.
- Maximum: 15 mg once weekly for adults, and 10 mg once weekly for children and teens aged 10 to under 18.
Mounjaro is injected under the skin of the abdomen or thigh, on the same day each week. Another person can inject it into the back of the upper arm. Use a different spot each week. You can change your injection day if there are at least 3 days (72 hours) between two doses.
Missed dose: take it as soon as you can if it is within 4 days (96 hours) of the missed dose. If more than 4 days have passed, skip it and take the next dose on your usual day. Do not change your dose without talking to your doctor.
Storage Instructions
Store Mounjaro in the refrigerator at 2°C to 8°C. Do not freeze it, and do not use it if it has been frozen. Protect it from light. If needed, a KwikPen can be kept out of the refrigerator, at no more than 30°C, for up to 30 days. Single-dose pens and vials can be kept out for up to 21 days. Throw out a KwikPen after four weekly doses. Keep out of reach of children.
Side Effects of Mounjaro
The most common side effects affect the stomach and gut. In clinical trials in adults with type 2 diabetes, they were reported by the following share of people on the 5 mg to 15 mg doses, compared with placebo:
- Nausea: about 12% to 18%, compared with 4% on placebo
- Diarrhea: about 12% to 17%, compared with 9%
- Decreased appetite: about 6% to 11%, compared with 1%
- Vomiting: about 5% to 9%, compared with 2%
- Indigestion: about 5% to 8%, compared with 3%
- Constipation: about 6% to 7%, compared with 1%
Burping, gas, heartburn, tiredness and reactions at the injection site were also reported. Stomach and gut effects are most common when starting Mounjaro or increasing the dose. In children and teens, vomiting, abdominal pain and low blood sugar were reported more often than in adults.
Get medical help right away if you have:
- Severe stomach pain that does not go away, with or without vomiting (possible pancreatitis)
- A lump or swelling in the neck, hoarseness, or trouble swallowing
- Signs of a serious allergic reaction, such as swelling of the face or throat or trouble breathing
- Vomiting or diarrhea that leaves you unable to keep fluids down
- Signs of low blood sugar (sweating, shakiness, confusion), mainly if you also take a sulfonylurea or insulin
Important Safety Information About Mounjaro
Thyroid tumours: the Canadian monograph carries a boxed warning. Tirzepatide caused thyroid C-cell tumours in rats. It is not known whether this happens in humans. Do not use Mounjaro if you or a family member have had medullary thyroid cancer, or if you have multiple endocrine neoplasia syndrome type 2 (MEN 2).
Allergy: do not use Mounjaro if you are allergic to tirzepatide or any ingredient in it. The Mounjaro KwikPen contains benzyl alcohol.
Pregnancy: do not use Mounjaro while pregnant. Stop it at least 1 month before a planned pregnancy.
Breastfeeding: in a study, tirzepatide was undetectable or at very low levels in breast milk. Its effect on a breastfed baby is not known. Talk to your doctor before breastfeeding while on Mounjaro.
Pancreatitis: stop the medicine and seek care if you develop severe, persistent abdominal pain.
Gallbladder problems: in placebo-controlled trials, acute gallbladder disease was reported in 0.6% of people on Mounjaro and in none on placebo.
Low blood sugar: the risk is higher when Mounjaro is used with a sulfonylurea or insulin. Take care when driving or using machines.
Kidneys: vomiting and diarrhea can cause dehydration, which can worsen kidney function. Drink fluids and tell your doctor if these effects persist.
Diabetic eye disease: a fast improvement in blood sugar can temporarily worsen diabetic retinopathy. Tell your doctor if you have eye problems from diabetes.
Surgery and procedures: Mounjaro slows stomach emptying. Tell your care team you take it before general anesthesia or deep sedation.
Stomach and heart: Mounjaro is used with caution in people with severe stomach or gut disease, such as severe gastroparesis. In trials it raised heart rate by 2 to 4 beats per minute on average.
Drug Interactions
Tell your doctor and pharmacist about everything you take, including non-prescription products. Points from the Canadian monograph:
- Birth control pills: Mounjaro can lower the amount of the pill your body absorbs. Switch to a non-oral method, or add a barrier method such as condoms, for 4 weeks after starting Mounjaro and for 4 weeks after each dose increase.
- Sulfonylureas and insulin: the risk of low blood sugar is higher. Your doctor may lower the dose of these medicines.
- Other medicines taken by mouth: Mounjaro slows stomach emptying, which could affect how other oral medicines are absorbed.
- GLP-1 medicines (such as semaglutide) and DPP-4 inhibitors: Mounjaro should not be used together with them.
- Medicines that raise heart rate: use with caution.
Brands & DIN Number of Mounjaro
Brand Names
- Mounjaro
- Mounjaro KwikPen
DIN (Drug Identification Numbers)
- 02551950
- 02551969
- 02551977
- 02551985
- 02551993
- 02552000
Key Takeaways
- 1Mounjaro is tirzepatide, a once-weekly injection authorized in Canada for type 2 diabetes in adults and in children aged 10 and older.
- 2It is not authorized in Canada for weight management. Zepbound is the tirzepatide product authorized for that use.
- 3Dosing starts at 2.5 mg weekly for 4 weeks and can increase in steps up to a maximum of 15 mg weekly in adults.
- 4Nausea, diarrhea, decreased appetite and vomiting are the most common side effects.
- 5Do not use it with a personal or family history of medullary thyroid cancer or MEN 2, or during pregnancy.
- 6It can make birth control pills less effective for 4 weeks after starting and after each dose increase.
- 7Mounjaro needs a prescription. BC residents can ask a BC-licensed doctor by phone whether it is right for them.
Frequently Asked Questions
Avee Editorial
Avee Editorial Team