Mounjaro
Getting started with Mounjaro: injections, sites and your first months
7 min read · Updated September 2026 · Reviewed by the Miva clinical team
Mounjaro (tirzepatide) was originally developed by Eli Lilly for type 2 diabetes, and is now a well-established tool for chronic weight management. It is a dual GIP and GLP-1 receptor agonist, meaning it mimics two gut hormones that suppress appetite, slow gastric emptying and signal fullness to the brain.
Alongside a calorie-reduced diet and more activity, tirzepatide has helped people lose up to around 20% of their body weight in clinical trials. This guide covers how to administer it, where to inject, and how to navigate the first few months in Canada.
How to take Mounjaro injections
Mounjaro is prescribed in gradually increasing strengths so your body can adapt. In Canada it is dispensed as single-use vials or pre-filled pens, depending on supply. Treatment normally starts at 2.5 mg once weekly for four weeks, then steps up to 5 mg.
From there your prescriber decides your maintenance dose — the strength that gives the most benefit with the fewest side effects. Mounjaro is a subcutaneous injection, given into the fatty tissue just under the skin. You can take it at any time of day, with or without food, but inject on the same day each week.
Which injection site is right for you?
No site makes the medicine stronger — pick the one you can reach comfortably, and rotate the exact spot every week to protect your skin.
- Abdomen: large surface area, easy to reach, usually the least painful. Stay at least 5 cm away from the navel.
- Front of the thigh: full visibility and control, good for self-injecting while seated.
- Back of the upper arm: discreet, but usually needs someone else to administer it.
Step by step
Feeling nervous before a first injection is normal. Always follow the leaflet supplied with your Canadian packaging.
- Take your vial or pen from the fridge and gather a syringe (if using vials), an alcohol swab and a sharps container
- Inspect the liquid — it should be clear and colourless to slightly yellow, with no cloudiness or particles
- Wash your hands and clean the chosen site with the alcohol swab, then let it dry
- Pinch the skin gently, insert the needle and deliver the full dose
- Hold in place for a few seconds, withdraw, and dispose of the needle in your sharps container
- Note the site you used so you rotate next week
The dosing schedule
Doses step up in 2.5 mg increments, with at least four weeks at each strength. Titration exists to let your digestive system acclimatise and reduce nausea, bloating and diarrhoea.
| Period | Weekly dose |
|---|---|
| Month 1 | 2.5 mg |
| Month 2 | 5 mg |
| Month 3 | 7.5 mg (if clinically appropriate) |
| Month 4 | 10 mg (if clinically appropriate) |
| Month 5+ | Maintenance, or continued titration up to 15 mg |
What results to expect
In a 72-week trial, average weight reduction was roughly 16% on 5 mg, 21% on 10 mg and 22% on 15 mg. Individual results vary considerably, and the maximum dose is not the goal — an effective, tolerable dose is.
Combine the medicine with protein-forward meals, resistance training and consistent sleep, and track how you feel and move rather than the scale alone.
Frequently asked questions
Can I inject Mounjaro in the same place each week?
You can use the same general area, such as the abdomen, but choose a different spot within it every week to avoid irritation and scar tissue.
What time of day should I inject?
Any time. Some people prefer the evening so they sleep through any initial nausea. Consistency of day matters more than time.
What if I miss a dose?
If your next dose is more than 72 hours away you can usually take the missed dose; otherwise skip it and resume your schedule. Never double up — check with your prescriber or pharmacist if you are unsure.
Mounjaro (tirzepatide) and Wegovy (semaglutide) are prescription-only medicines in Canada. This page is general information, not medical advice — a Canadian-licensed clinician reviews every assessment and decides whether treatment is suitable for you.
Join the Miva list
Sign up now
Leave your email and we’ll let you know the moment consultations open, plus early access to Miva treatment pricing.
No spam. Unsubscribe at any time. We never share your details.