Mounjaro vs Ozempic: Key Differences, Cost, and Side Effects

Mounjaro and Ozempic are two of the most widely prescribed medications used for weight management in Canada. While officially approved for managing Type 2 diabetes, they are commonly prescribed “off-label” for weight loss. If you’re considering speaking with a doctor about Mounjaro or Ozempic, you’re probably wondering how they compare.

In the first head-to-head clinical trial comparing these medications, published in the New England Journal of Medicine, Mounjaro produced an average weight loss of 20.2% compared to 13.7% with semaglutide (the active ingredient in Ozempic). That’s a meaningful difference, but it doesn’t automatically make Mounjaro the right choice for everyone.

In this article, we provide a detailed Mounjaro vs Ozempic comparison. We’ll cover how they work, what the clinical evidence says about weight loss, side effects, and what each medication costs in Canada.

How Mounjaro and Ozempic Work

You’ll often hear both Mounjaro and Ozempic referred to broadly as “GLP-1s.” But they technically belong to a wider class of medications known as incretin mimetics. 

Both medications work by mimicking the hormones your body naturally releases after eating, which helps regulate appetite and blood sugar. However, Ozempic and Mounjaro target these hormone pathways in different ways.

Ozempic (semaglutide) is a GLP-1 receptor agonist. It activates the GLP-1 hormone receptor, which slows gastric emptying, reduces appetite by acting on hunger centres in the brain, and helps regulate blood sugar levels. You can read more about how it works in our complete Ozempic article.

Mounjaro (tirzepatide) is a dual GIP and GLP-1 receptor agonist. It activates the same GLP-1 receptor as Ozempic, but it also activates the GIP receptor, which plays a role in how your body processes and stores fat. This dual mechanism is why Mounjaro is sometimes referred to as a “twincretin” or “dual agonist.” For a deeper dive, see our full Mounjaro article.

The practical takeaway is that Mounjaro targets two biological pathways involved in weight regulation rather than one. This dual action is believed to be a key reason why clinical trials show greater weight loss with Mounjaro compared to Ozempic.

Mounjaro vs Ozempic for Weight Loss

The most direct comparison between Ozempic vs Mounjaro for weight loss comes from the SURMOUNT-5 trial, a 72-week clinical study that tested the maximum tolerated doses of both medications head-to-head in adults with obesity (without diabetes). A total of 751 participants were enrolled.

(Note: While this specific trial used the weight-loss branded versions of these drugs, Zepbound and Wegovy, the active ingredients and dosing are identical to Mounjaro and Ozempic).

The results were clear. Participants taking Mounjaro lost an average of 20.2% of their body weight (about 50 lbs), compared to 13.7% (about 33 lbs) with semaglutide. That represents roughly 47% more relative weight loss with Mounjaro.

The difference in Mounjaro vs Ozempic becomes even more apparent when looking at how many participants hit specific weight loss milestones:

Mounjaro vs Ozempic Weight Loss Table

Data from the SURMOUNT-5 phase 3b trial, published in the New England Journal of Medicine.

These are significant differences. Nearly half of Mounjaro participants lost more than 20% of their starting weight — a level of weight loss that was historically only achievable through bariatric surgery.

It’s worth noting that the study found women tended to lose more weight than men with both medications. Also, weight loss with Ozempic tended to plateau earlier (around 52 to 60 weeks), while Mounjaro continued producing results for a longer period before plateauing.

Both medications are effective. The question is whether the additional weight loss with Mounjaro is clinically meaningful for your situation. This is something your doctor can help you assess.

Mounjaro vs Ozempic for Type 2 Diabetes

While most people searching “Mounjaro vs Ozempic” online are interested in weight loss, both medications are officially approved for Type 2 diabetes management in Canada. 

Here’s a summary of the results of a head-to-head clinical trial comparing Mounjaro and the 1.0 mg dose of Ozempic in patients with Type 2 diabetes over a 40-week period:

• Mounjaro produced greater reductions in HbA1c (a measure of long-term blood sugar control) at all doses tested.
• The highest dose of Mounjaro achieved an average HbA1c reduction of 2.46%, compared to 1.86% with Ozempic.
• About half of the patients on the highest Mounjaro dose achieved an HbA1c below 5.7% — a level considered non-diabetic — compared to roughly 20% of those taking Ozempic.

If diabetes management is your primary concern, this is an important conversation to have with your doctor. Both Mounjaro and Ozempic offer strong glycemic control, but they may differ in how they fit into your overall treatment plan.

Mounjaro vs Ozempic Side Effects

The side effects of Mounjaro and Ozempic are broadly similar, as both medications work on the same class of hormone receptors. For most patients, side effects tend to be most noticeable during the first few weeks of treatment or immediately after a dose increase.

Common Ozempic and Mounjaro Side Effects

Because Ozempic and Mounjaro slow down how quickly food leaves your stomach, the most frequently reported side effects are gastrointestinal, including:

• Nausea
• Diarrhea
• Vomiting
• Constipation

What’s interesting is that despite producing more weight loss, Mounjaro doesn’t appear to cause worse side effects than Ozempic. Researchers believe this may be because GIP receptor activation (which Mounjaro has but Ozempic doesn’t) has an anti-nausea effect that partially offsets the gastrointestinal discomfort caused by GLP-1 activation.

Dosing to Reduce Side Effects: Ozempic vs Mounjaro

To minimize side effects, both Mounjaro and Ozempic require a gradual dose titration. This means you start at a low dose and increase it every four weeks to give your body time to adjust. Skipping this gradual process significantly increases the risk of severe side effects.

Here are the standard starting and maximum doses for Ozempic vs Mounjaro:

A Notable Difference: Oral Contraceptives

One major side effect difference to be aware of is that due to its strong effect on gastric emptying, Mounjaro can reduce the absorption of oral contraceptive pills.

Women taking oral birth control should discuss alternative contraception methods with their doctor before starting Mounjaro. This interaction is not a concern with Ozempic, which may factor into a final decision on medication choice.

As with any prescription medication, the full picture of potential side effects should be reviewed with your healthcare provider before starting treatment.

Mounjaro vs Ozempic Cost Canada

Cost is often the deciding factor for Canadians evaluating Mounjaro vs Ozempic, and the pricing structures are quite different.

Ozempic uses a flat pricing model in Canada — you pay roughly the same amount regardless of your dose. A four-week supply typically costs between $253 and $308 CAD depending on your pharmacy, and this stays relatively consistent whether you’re on the 0.25 mg starting dose or the 2.0 mg maximum dose. (Note: Generic versions of Ozempic are expected to become available in Canada in late 2026, which could significantly reduce costs).

Mounjaro uses a dose-dependent pricing model — the cost increases as your dose goes up. The starting doses (2.5 mg and 5.0 mg) cost approximately $300 CAD per month, but this can climb to $450–$500+ at higher doses (12.5 mg and 15.0 mg). Eli Lilly offers a patient support program through mymounjaro.ca that may provide discounts of 25–40% depending on the dose.

Provincial and Private Insurance Coverage

Because Ozempic and Mounjaro are officially approved as diabetes medications, neither is typically covered by provincial drug plans or private insurance when prescribed strictly for weight loss. 

However, if you are looking for insurance coverage specifically for weight management, some private health benefits will cover Ozempic and Mounjaro’s weight-loss-approved counterparts: Wegovy (semaglutide) and Zepbound (tirzepatide). Currently, Canadian provincial drug plans do not provide coverage for Wegovy or Zepbound.

Bottom Line: Mounjaro vs Ozempic Cost

In practical terms, Ozempic offers more predictable monthly out-of-pocket costs for Canadians, while Mounjaro’s cost depends on the dose you ultimately need to achieve your goals. Neither medication is likely to be covered by provincial drug plans when prescribed for weight loss. 

Cost of medications is an important factor to discuss when creating a longer-term weight loss plan with your doctor.

Health Benefits Beyond Weight Loss: Mounjaro vs Ozempic

Both Mounjaro and Ozempic are still being actively studied for health benefits that extend beyond weight loss alone. These medications appear to influence several areas of metabolic health, and research is ongoing in areas including cardiovascular disease, kidney health, liver disease (MASH), and sleep apnea.

Where Ozempic Has More Evidence

Semaglutide (the active ingredient in Ozempic) has a head start when it comes to proven benefits beyond weight loss. The SELECT trial demonstrated a 20% reduction in major cardiovascular events (such as heart attack and stroke) in non-diabetic patients with established heart disease. This led to an explicit approval of semaglutide for cardiovascular risk reduction in Canada.

Where Mounjaro Is Catching Up

Trials are currently underway investigating the cardiovascular effects of tirzepatide (the active ingredient in Mounjaro), but haven’t reported final results yet. Until those prospective trials conclude, semaglutide remains the evidence-based choice for patients whose doctor specifically wants to address cardiovascular risk.

The Bigger Picture for GLP-1 Health Benefits

This class of medications Ozempic and Mounjaro belong to seems to have several health benefits beyond weight reduction alone. Your doctor can discuss which of these additional benefits, if any, are relevant to your health situation.

What About Wegovy and Zepbound?

If you’ve been researching weight loss medications, you may have also come across Wegovy and Zepbound. Rather than expand this article into a four-way “Mounjaro vs Ozempic vs Wegovy vs Zepbound” comparison, here’s a quick explanation of the latter two so you know where they fit in.

Wegovy contains the same active ingredient as Ozempic — semaglutide. However, Wegovy is specifically approved for weight management in Canada (rather than diabetes) and is available at a higher maximum dose (2.4 mg, compared to Ozempic’s 2.0 mg). We cover this in detail in our complete Wegovy article.

Zepbound contains the same active ingredient as Mounjaro, tirzepatide, and is specifically approved for weight management in Canada. Unlike Wegovy, which offers a higher dose than its diabetes counterpart, Zepbound and Mounjaro share the exact same dosing schedule and maximum dose (15 mg).

Much of the clinical data in this article applies to the active ingredients (semaglutide and tirzepatide) regardless of which brand name is used. The differences between the brands primarily come down to regulatory approvals, available doses, and insurance coverage pathways.

In Canada, many doctors prescribe Ozempic or Mounjaro off-label for weight loss, though Wegovy and Zepbound are the official, on-label options for weight management.

Frequently Asked Questions About Ozempic vs Mounjaro

Here are some common questions people ask when comparing Mounjaro and Ozempic.

Is Mounjaro stronger than Ozempic? 

In terms of average weight loss, yes. Clinical trial data shows Mounjaro produces about 47% more relative weight loss than semaglutide at maximum doses. However, “stronger” doesn’t always mean “better for you” — the right medication depends on your individual health profile, goals, and circumstances.

Can you switch from Ozempic to Mounjaro? 

Yes, switching is possible under medical supervision. Your doctor will determine the appropriate starting dose of Mounjaro based on your current Ozempic dose and overall response. It’s not a direct dose-for-dose conversion, so medical guidance is essential.

Which has fewer side effects — Mounjaro or Ozempic? 

The side effect profiles are similar, with gastrointestinal symptoms (nausea, diarrhea, vomiting) being most common for both. However, in the SURMOUNT-5 trial, fewer participants stopped Mounjaro due to side effects (2.7%) compared to Ozempic (5.6%), possibly due to Mounjaro’s GIP-mediated anti-nausea effect.

Do I need a prescription for Mounjaro or Ozempic in Canada? 

Yes, both medications require a prescription from a licensed healthcare provider in Canada. They are not available over the counter.

Will I regain weight if I stop taking Mounjaro or Ozempic? 

Research suggests that weight regain is common after discontinuing either medication, as the biological mechanisms that suppress appetite return to baseline. This is why these medications are typically considered long-term treatments, and why ongoing medical follow-up and concurrent lifestyle change is important.

Mounjaro vs Ozempic: Which is Right for You?

There isn’t a universal answer to whether Mounjaro or Ozempic is the better choice. The clinical data shows that Mounjaro produces greater weight loss on average, but both medications are effective, and several factors beyond raw efficacy should influence the decision.

When considering Ozempic vs Mounjaro, your doctor will consider things like:

• Your overall health profile
• Whether you have Type 2 diabetes or cardiovascular risk factors
• What other medications you’re taking (particularly oral contraceptives)
• Your budget and insurance coverage
• How your body responds during the titration process

Some patients do better on one medication than the other for reasons that aren’t always predictable from the data alone.

What matters most is that you’re making this decision in consultation with a qualified healthcare provider who can evaluate your full medical history and help you weigh the benefits and trade-offs. Both Mounjaro and Ozempic are powerful medications that require medical supervision — this isn’t a decision to make based on internet research alone.

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