What is Ozempic?

Ozempic is a Health Canada-approved medication for adults with Type 2 diabetes. The active ingredient is semaglutide. It lowers blood sugar, helps manage weight, and reduces the risk of major cardiovascular events.

How does Ozempic work?

Ozempic works on several fronts:

1. Stimulates insulin secretion: when you eat, your blood sugar rises, and Ozempic triggers your pancreas to release insulin.
2. Reduces glucagon, the hormone that raises blood sugar, so blood sugar stays steadier.
3. Delays gastric emptying, so food leaves your stomach more slowly. You feel full longer and eat less.
4. Lowers blood glucose overall by combining the above.

What is Mounjaro?

Like Ozempic, Mounjaro is Health Canada-approved for Type 2 diabetes. The active ingredient is tirzepatide, which is different from semaglutide. Mounjaro outperforms Ozempic on both blood sugar control and weight loss. It also costs more and has a heavier side effect profile.

How does Mounjaro work?

Mounjaro works differently from most diabetes drugs:

1. Dual GIP and GLP-1 receptor agonist: where Ozempic targets only GLP-1, Mounjaro hits both receptors.
2. Suppresses glucagon and boosts insulin secretion, lowering blood sugar more effectively.
3. Targets two pathways at once, giving more thorough blood sugar control.
4. Drives more weight loss in clinical trials, partly because the dual receptor action controls appetite better.

Mounjaro is a strong choice for Type 2 diabetes, but the higher cost and more intense side effects are part of the trade.

How effective are Ozempic and Mounjaro?

Across multiple studies, Mounjaro comes out ahead on both weight loss and blood sugar control. Ozempic is still effective, especially at lowering A1C and reducing cardiovascular risk, but Mounjaro tends to produce better results.

Clinical trial comparisons

Phase 3 SURPASS-2 study

The Phase 3 SURPASS-2 study compared Mounjaro (tirzepatide) and Ozempic (semaglutide) over 40 weeks. Participants were adults with Type 2 diabetes whose blood sugar wasn't controlled on metformin alone. Average starting A1C was 8.3% and average weight was about 207 pounds.

• A1C Reduction Results:
  • Mounjaro 5 mg, 10 mg, and 15 mg injections lowered A1C by 2.0% to 2.3%.
  • Ozempic 1 mg injections reduced A1C by 1.9%.
• Weight Loss Results:
  • Participants on Mounjaro lost between 17 to 25 pounds.
  • Those on Ozempic lost about 13 pounds.

EASD meta-analysis

A meta-analysis presented at the European Association for the Study of Diabetes (EASD) meeting compared tirzepatide (Mounjaro) and semaglutide (Ozempic) across 22 randomized controlled trials with 18,472 participants.

• Effectiveness Comparison:
  • Tirzepatide 15 mg was the most effective in lowering A1C, followed by tirzepatide 10 mg, and then semaglutide 2 mg.
  • Each tirzepatide dose reduced A1C more than the respective semaglutide doses.
• A1C and Weight Loss Outcomes:
  • Tirzepatide 10 mg and 15 mg doses were more effective in lowering body weight than semaglutide 1 mg and 2 mg doses.
  • Tirzepatide 5 mg was more effective than semaglutide 0.5 mg and 1 mg.
• Side Effect Profiles:
  • Gastrointestinal side effects were common with both drugs.
  • Tirzepatide had a higher risk for nausea, vomiting, and diarrhea at higher doses.

Why consider Mounjaro for weight loss?

Greater weight loss than Ozempic

In the SURPASS-2 study, Mounjaro users lost 17 to 25 pounds, while Ozempic users lost about 13 pounds. If big weight loss is the goal, that's a meaningful gap.

Dual-action mechanism

Mounjaro hits both GIP (glucose-dependent insulinotropic polypeptide) and GLP-1 (glucagon-like peptide-1) receptors. The dual action lowers blood sugar more effectively and drives more weight loss.

• GIP and GLP-1:
  • GIP: Lowers blood sugar by stimulating insulin release.
  • GLP-1: Slows down digestion, making you feel fuller longer and eat less.

Two mechanisms in one drug can mean better results on both weight and blood sugar.

Potentially better long-term weight management

Mounjaro's dual action may also help you keep the weight off:

• Feel full faster and longer, so you eat less.
• Better blood sugar control reduces cravings and binges.

Why consider Ozempic for weight loss?

Proven cardiovascular benefits

Ozempic is approved to lower the risk of major cardiovascular events (heart attacks, strokes) in adults with Type 2 diabetes. If you have diabetes and worry about heart health, that's a real reason to consider it.

• Cardiovascular Outcomes:
  • Heart Attack Reduction: Studies show a significant decrease in heart attacks among Ozempic users.
  • Stroke Prevention: Reduces the risk of strokes, adding another layer of protection for your heart.

Established safety profile

Ozempic has been on the market longer than Mounjaro, so there's more long-term data on its effects.

• Health Canada approvals: Ozempic has been tested and approved for multiple uses, including cardiovascular risk reduction.
• Long-term data: more years of evidence on safety and effectiveness.

Effective at lowering A1C

Ozempic does a good job of lowering A1C, which measures long-term blood sugar control. Useful for Type 2 diabetes.

• A1C Reduction:
  • 0.5 mg Dose: Lowers A1C by about 1.1% on average.
  • 1 mg Dose: Lowers A1C by about 1.5% on average.
  • 2 mg Dose: Lowers A1C by about 1.8% on average.

Lower A1C helps prevent diabetes complications like nerve damage, heart disease, and kidney problems.

What about risks and side effects?

Common GI side effects

Both drugs can cause gastrointestinal (GI) issues, especially when you start the medication or increase the dose.

Nausea:

• Mounjaro: 12% to 18% of users.
• Ozempic: 16% to 20% of users.

Diarrhea:

• Mounjaro: 12% to 17% of users.
• Ozempic: 8.5% to 8.8% of users.

Vomiting:

• Mounjaro: 5% to 9% of users.
• Ozempic: 5% to 9.2% of users.

Constipation:

• Mounjaro: 6% to 7% of users.
• Ozempic: 3.1% to 5% of users.

How to manage GI symptoms:

• Ramp up the dose slowly.
• Drink plenty of water to help with constipation and diarrhea.
• Eat smaller, more frequent meals to reduce nausea and vomiting.

Serious side effects and Health Canada warnings

Less common, but worth knowing:

Thyroid tumors:

• Boxed warning: both drugs carry a boxed warning for potential thyroid tumors, including cancer, observed in animal studies.
• Do not use if you or your family have a history of medullary thyroid carcinoma (MTC) or Multiple Endocrine Neoplasia syndrome type 2 (MEN 2).

Symptoms to Watch For:

• Neck Mass: Any swelling or lump in the neck.
• Trouble Swallowing: Difficulty swallowing food or liquids.
• Shortness of Breath: Unexplained breathing issues.
• Persistent Hoarseness: Changes in your voice that don't go away.

Other Serious Side Effects:

• Pancreatitis: Inflammation of the pancreas, causing severe stomach pain.
• Gallbladder Disease: Issues like gallstones can occur, leading to abdominal pain and digestive problems.

How to handle thyroid tumor risks

If you or your family have a history of thyroid issues, talk to your doctor before starting either drug.

Preventive measures:

• Regular check-ups to monitor for thyroid changes.
• Routine blood tests to catch abnormalities early.
• Ultrasounds for imaging the thyroid.

Recent updates: ileus

Health Canada recently added ileus (intestinal blockage without physical obstruction) to the side effect list for both drugs.

Symptoms of Ileus:

• Abdominal Swelling: Noticeable bloating or swelling in the stomach area.
• Fullness and Gas: Feeling unusually full or gassy.
• Stomach Pain: Cramping or pain in the abdominal area.
• Breath Odor: Unusual odor from your breath.
• Constipation: Severe constipation or inability to pass gas.
• Vomiting: Occasional vomiting.

What to do:

• Seek medical help right away if you have these symptoms.
• Talk to your doctor about your risk for ileus and how to lower it.

Cost and insurance coverage

Both drugs are expensive. Without insurance, Ozempic runs around $220 to $265 per month and Mounjaro is around $380 to $480 per month. Prices vary slightly by pharmacy. We usually recommend Costco Pharmacy.

Provincial insurance like OHIP doesn't cover either drug for weight loss in Canada, but private insurance through an employer often does.

Which works better for weight loss?

A real-world Truveta study found:

• Tirzepatide users were 1.8 times more likely to hit 5% weight loss, 2.4 times more likely to hit 10%, and three times more likely to hit 15% than semaglutide users.
• By timeframe:
  • 3 months: 5.9% average weight loss on tirzepatide vs. 3.6% on semaglutide.
  • 6 months: 10.1% vs. 5.9%.
  • 1 year: 15.2% vs. 7.9%.

What to consider when choosing

Side effects:

• Mounjaro: higher rates of nausea, vomiting, and diarrhea, but more weight loss.
• Ozempic: fewer GI side effects, but less weight loss.

Cost:

• Mounjaro: about $380 to $480 per month.
• Ozempic: about $220 to $265 per month.

What the experts say

Nick Stucky, MD, PhD:

• Stresses the value of real-world data.
• Notes that GLP-1 drugs have changed treatment for Type 2 diabetes and obesity.

Tyler Gluckman, MD, MHA:

• Calls for timely data to guide patient care.
• Emphasizes real-world effectiveness, not just trial results.

It's also worth looking at other GLP-1 agonists like Saxenda, Rybelsus, and Wegovy, which may offer different benefits or better insurance coverage. Talk to a healthcare provider to find the right fit for your health and budget.

Disclaimer: This blog post is intended for educational purposes only and should not be taken as medical advice. Always consult your healthcare provider for personal health concerns.