Key Takeaways
- Mounjaro (tirzepatide) produces more weight loss than Ozempic (semaglutide) — 18–22% vs 12–14% average body weight loss
- Mounjaro is a dual GLP-1/GIP agonist (two mechanisms) vs Ozempic's single GLP-1 mechanism — this drives the superior results
- Mounjaro costs more: RM2,500–3,500/month vs RM1,200–1,500/month for Ozempic in Malaysia
- Side effect profiles are similar — GI effects dominate both, with Mounjaro showing slightly less nausea in some studies
- Most Malaysian doctors recommend starting with Ozempic (lower cost, wider availability) and switching to Mounjaro if needed
Medical disclaimer: This article is for informational purposes only. Both medications are prescription drugs. Consult your doctor to determine which is appropriate for your situation.
The Fundamental Difference: Single vs Dual Mechanism
This is the most important thing to understand about the Mounjaro vs Ozempic comparison:
Ozempic (Semaglutide) — GLP-1 Agonist
Activates one incretin receptor: GLP-1. This suppresses appetite, slows gastric emptying, and improves insulin dynamics. It's powerful — semaglutide proved GLP-1 agonists could produce surgery-level weight loss in some patients.
Mounjaro (Tirzepatide) — GLP-1/GIP Dual Agonist
Activates two incretin receptors: GLP-1 and GIP (glucose-dependent insulinotropic polypeptide). The GIP component adds:
- Enhanced fat metabolism: GIP signalling directly affects fat tissue, promoting lipid mobilisation
- Improved insulin sensitivity: The dual action appears to produce better glucose regulation than GLP-1 alone
- Potentially different appetite pathways: The combined signalling may suppress appetite through slightly different neural circuits
Think of it this way: Ozempic turns one dial to 10. Mounjaro turns two dials to 8 each, producing a greater combined effect.
Head-to-Head: The Clinical Trial Data
SURMOUNT Trials (Tirzepatide/Mounjaro)
| Trial | Dose | Duration | Average Weight Loss |
|---|---|---|---|
| SURMOUNT-1 | 5mg | 72 weeks | 15.0% |
| SURMOUNT-1 | 10mg | 72 weeks | 19.5% |
| SURMOUNT-1 | 15mg | 72 weeks | 20.9% |
| SURMOUNT-2 (T2D) | 15mg | 72 weeks | 14.7% |
STEP Trials (Semaglutide/Wegovy)
| Trial | Dose | Duration | Average Weight Loss |
|---|---|---|---|
| STEP 1 | 2.4mg (Wegovy dose) | 68 weeks | 14.9% |
| STEP 2 (T2D) | 2.4mg | 68 weeks | 9.6% |
| STEP 3 (+ behaviour therapy) | 2.4mg | 68 weeks | 16.0% |
Note: Ozempic's maximum registered dose is 1mg (sometimes 2mg), not 2.4mg. At 1mg, weight loss is approximately 12–14%. We include Wegovy (2.4mg) data for full semaglutide comparison.
The Direct Comparison
| Metric | Mounjaro (15mg) | Ozempic (1mg) | Wegovy (2.4mg) |
|---|---|---|---|
| Average weight loss | ~20.9% | ~12–14% | ~14.9% |
| Patients losing ≥20% | ~57% | ~15–20% | ~32% |
| HbA1c reduction | ~2.1% | ~1.5% | ~1.0% |
| Nausea rate | ~24–31% | ~40–44% | ~44% |
| Discontinuation due to side effects | ~6–7% | ~7% | ~7% |
Key takeaway: Mounjaro at maximum dose produces roughly 6–7 percentage points more weight loss than Wegovy (2.4mg semaglutide), and the gap widens compared to standard Ozempic (1mg). The difference is clinically significant — for an 85kg person, it's the difference between losing ~11kg (Ozempic) and ~18kg (Mounjaro).
Side Effect Comparison
Both drugs share similar GI side effect profiles, but with notable differences:
Nausea
- Ozempic/Wegovy: ~44% of patients — tends to be more intense and persistent
- Mounjaro: ~24–31% — generally milder. Some researchers hypothesise the GIP component counterbalances some of the GLP-1-driven nausea
Diarrhea
- Ozempic: ~30%
- Mounjaro: ~17–23% — slightly less common
Constipation
- Similar rates across both (~15–24%)
Injection Site Reactions
- Mounjaro: Slightly higher rate of injection site reactions
- Generally mild — redness, itching at injection point
Serious Side Effects
- Both carry similar warnings: pancreatitis, gallbladder disease, thyroid C-cell tumour risk (rodent data)
- No evidence that one has significantly worse serious side effects than the other
Malaysian patients frequently report: Mounjaro is subjectively "easier" on the stomach than Ozempic. This is consistent with the trial data showing lower nausea rates. However, individual responses vary — some patients tolerate Ozempic perfectly but struggle with Mounjaro, and vice versa.
For detailed side effect management strategies, see our Ozempic side effects guide (strategies apply to both medications).
Cost Comparison in Malaysia (2026)
| Factor | Mounjaro | Ozempic |
|---|---|---|
| Starting dose cost/month | RM2,500–2,800 (2.5mg) | RM1,200–1,400 (0.25mg) |
| Maintenance dose cost/month | RM3,000–3,500 (10–15mg) | RM1,200–1,500 (1mg) |
| Annual cost (maintenance) | RM36,000–42,000 | RM14,400–18,000 |
| Price per % body weight lost | ~RM170–200 per 1% | ~RM110–130 per 1% |
Mounjaro costs roughly double Ozempic in Malaysia. When you factor in the extra weight loss, the "cost per kilogram lost" is closer — but Ozempic still offers better bang-for-ringgit for most patients.
For a comprehensive pricing breakdown across all options, see our weight loss injection prices guide.
Availability in Malaysia
Ozempic
- NPRA registered for type 2 diabetes
- Widely available at most private clinics and hospitals
- Stable supply chain (Novo Nordisk has strong Malaysian distribution)
- Occasional shortages during demand spikes, but generally reliable
Mounjaro
- NPRA registration status: Available through select private clinics; full registration still expanding
- More limited availability than Ozempic — not all clinics stock it
- Manufactured by Eli Lilly (vs Novo Nordisk for Ozempic)
- Supply has improved significantly since 2024 but can still be inconsistent in some areas
- East Malaysia availability is particularly limited
Mounjaro Dosing vs Ozempic Dosing
Mounjaro Titration
| Weeks | Dose |
|---|---|
| Weeks 1–4 | 2.5mg weekly |
| Weeks 5–8 | 5mg weekly |
| Weeks 9–12 | 7.5mg weekly |
| Weeks 13–16 | 10mg weekly |
| Week 17+ (if needed) | 12.5mg or 15mg weekly |
Ozempic Titration
| Weeks | Dose |
|---|---|
| Weeks 1–4 | 0.25mg weekly |
| Weeks 5–8 | 0.5mg weekly |
| Week 9+ | 1mg weekly (max standard dose) |
Mounjaro has a longer titration period (16+ weeks to reach max vs 8+ weeks for Ozempic). Some patients find the weight loss onset slower with Mounjaro, but the eventual results are superior.
Switching Between Mounjaro and Ozempic
Ozempic → Mounjaro
The most common switch direction. Reasons include:
- Weight loss plateau on Ozempic 1mg — wanting to push further
- Intolerable GI side effects on semaglutide — hoping tirzepatide is better tolerated
- Desire for the dual-mechanism approach
Protocol: Stop Ozempic, start Mounjaro at 2.5mg the following week. Begin standard titration. Some patients report a brief "gap" in appetite suppression during the transition.
Mounjaro → Ozempic
Less common, but happens when:
- Cost becomes prohibitive — switching to the cheaper option
- Mounjaro supply issues — Ozempic is more reliably available
- Side effects specific to tirzepatide
Protocol: Stop Mounjaro, start Ozempic at an appropriate dose (your doctor will determine based on your Mounjaro dose and response). Expect some appetite return during transition.
Which Should You Try First?
Start with Ozempic if:
- Budget matters — roughly half the cost of Mounjaro
- First time on GLP-1s — it's the most studied, most available, and you can always upgrade
- Your target weight loss is moderate (10–15%) — Ozempic can achieve this for many patients
- You have type 2 diabetes — Ozempic has the strongest diabetes-specific evidence (SUSTAIN programme)
- You want cardiovascular protection — the SELECT trial specifically demonstrated cardiovascular benefits for semaglutide in obesity
Start with Mounjaro if:
- You need maximum weight loss — BMI >35, significant comorbidities, wanting to avoid bariatric surgery
- Budget isn't a major constraint
- You've tried semaglutide and plateaued or couldn't tolerate it
- You have severe insulin resistance — the dual mechanism offers superior glycaemic control
- You're particularly concerned about nausea — Mounjaro may be slightly better tolerated
The Practical Malaysian Recommendation
Most experienced weight management doctors in Malaysia recommend:
- Start with Ozempic (wider availability, lower cost, strong evidence base)
- Give it 6 months at maximum tolerated dose
- Assess results — if you've achieved your goals, continue on Ozempic
- If results are insufficient, switch to Mounjaro for the additional weight loss potential
This stepwise approach saves money for patients who respond well to Ozempic (many do) while keeping Mounjaro as a powerful second-line option.
The Future: What's Coming Next
Both drug classes are evolving rapidly:
- Zepbound (tirzepatide for obesity): Eli Lilly's obesity-specific branding of tirzepatide, similar to the Ozempic/Wegovy distinction. Expanding into new markets
- Retatrutide: Eli Lilly's triple agonist (GLP-1/GIP/glucagon) — Phase 2 showed up to 24% weight loss. Could surpass Mounjaro
- Oral tirzepatide: In development — would make Mounjaro's benefits available without injections
- CagriSema (Novo Nordisk): Semaglutide + cagrilintide (amylin analogue) — Phase 3 ongoing, targeting >20% weight loss
Frequently Asked Questions
Can I combine Mounjaro and Ozempic?
No. You should not take two GLP-1-based medications simultaneously. This would increase side effects without proportional benefit and isn't supported by any clinical data.
Which has less "Ozempic face"?
Facial volume loss is proportional to total weight loss, not the specific medication. Since Mounjaro produces more weight loss, "Ozempic face" (really "weight loss face") may actually be more noticeable. The same prevention strategies apply: protein, slower rate of loss, hydration.
Is Mounjaro worth the extra cost?
It depends on your response to Ozempic. If you're achieving good results on Ozempic, there's no reason to spend more. If you've plateaued and need further weight loss, the additional RM1,000–2,000/month for Mounjaro may be justified by the 6–8 percentage points of additional weight loss.
Which is better for someone with PCOS?
Both improve metabolic markers associated with PCOS (insulin resistance, androgen levels). Mounjaro's dual mechanism may offer slightly better insulin sensitisation, but both are effective. Discuss with your endocrinologist.
The Bottom Line
Mounjaro wins on raw weight loss numbers. Ozempic wins on cost, availability, and depth of evidence. For most Malaysians, the practical answer is: try Ozempic first, switch to Mounjaro if needed.
Both are remarkable medications that have transformed obesity medicine. The "better" choice depends entirely on your individual circumstances — BMI, budget, comorbidities, and how your body responds. Work with your doctor, track your progress, and don't hesitate to switch if your current medication isn't delivering the results you need.
For more on all available options, see our complete GLP-1 weight loss guide and three-way comparison.