What is Mounjaro?
Mounjaro is the brand name for tirzepatide, manufactured by American pharmaceutical company Eli Lilly. It's the first medication in a new class called dual GIP/GLP-1 receptor agonists — it targets two appetite-regulating pathways simultaneously rather than just one.
This dual mechanism appears to explain why Mounjaro produces significantly more weight loss than single-target GLP-1 medications like Wegovy and Ozempic. In head-to-head style comparisons (cross-trial, not direct), Mounjaro shows approximately 4–6 percentage points more weight loss than semaglutide.
Mounjaro is TGA-approved for two indications in Australia:
- Chronic weight management in adults with BMI ≥30 (or ≥27 with comorbidity)
- Type 2 diabetes — improving blood sugar control alongside weight loss
It's administered as a once-weekly subcutaneous injection using a pre-filled, single-use pen.
How does Mounjaro work?
Unlike Wegovy (which targets only GLP-1 receptors), Mounjaro activates both GLP-1 and GIP receptors:
- GLP-1 (glucagon-like peptide-1): Reduces appetite, slows gastric emptying, regulates blood sugar. This is the same pathway Wegovy and Ozempic target.
- GIP (glucose-dependent insulinotropic polypeptide): An additional gut hormone involved in energy balance, fat metabolism, and insulin secretion. Research suggests GIP activation may enhance fat oxidation and energy expenditure beyond what GLP-1 alone achieves.
The combined effect is more profound appetite suppression, greater metabolic changes, and ultimately more weight loss. Patients commonly report strong appetite reduction within the first few weeks, with many describing feeling satisfied with much smaller portions and experiencing reduced cravings for calorie-dense foods.
Expected weight loss results
Mounjaro's clinical data comes from the SURMOUNT programme:
SURMOUNT-1 (main trial)
- 2,539 adults with BMI ≥30 (or ≥27 with comorbidity), without diabetes
- Average weight loss at 15mg dose: 22.5% of body weight over 72 weeks
- At the 10mg dose: 19.5% average weight loss
- Over 50% of participants lost 20%+ of body weight at the highest dose
- Over a third lost 25% or more
For context, a person weighing 100kg could expect to lose approximately 20–22kg over 17 months. Some participants in the trial lost over 30% of their body weight — approaching results previously only achievable with bariatric surgery.
How this compares
| Medication | Avg. weight loss | % losing ≥20% |
|---|---|---|
| Mounjaro (15mg) | ~22% | ~50%+ |
| Wegovy (2.4mg) | ~15% | ~33% |
| Duromine | 5–10% | <5% |
| Contrave | 5–10% | <5% |
Dosage and escalation schedule
Mounjaro uses a 20-week escalation — slightly longer than Wegovy's 16 weeks:
| Weeks | Dose | What to expect |
|---|---|---|
| 1–4 | 2.5mg | Starting dose. Usually well tolerated. Mild appetite changes. |
| 5–8 | 5mg | Appetite suppression more noticeable. Some nausea possible. |
| 9–12 | 7.5mg | Significant weight loss may begin. GI effects may peak. |
| 13–16 | 10mg | Strong effects. Most have adjusted by this point. |
| 17–20 | 12.5mg | Approaching maximum dose. |
| 21+ | 15mg | Maximum dose. Not all patients need to reach this level. |
Your doctor will titrate based on your response and tolerability. Some patients achieve excellent results at 10mg and don't need to increase further — which also saves money since lower doses cost less.
Step-by-step injection guide →
Side effects
Similar gastrointestinal profile to other GLP-1 medications, but with notably lower nausea rates:
- Nausea: ~29% (compared to ~44% with Wegovy)
- Diarrhoea: ~23%
- Decreased appetite: ~20% (intended effect)
- Vomiting: ~12% (compared to ~24% with Wegovy)
- Constipation: ~16%
- Injection site reactions: ~5%
The significantly lower nausea rate is a real advantage for tolerability. Side effects are mostly confined to the escalation phase and improve over time.
Cost in Australia
Mounjaro is only available on private prescription — there is no PBS listing and no prospect of one for weight management currently.
| Provider | Monthly cost | Consult fee | Delivery | Notes |
|---|---|---|---|---|
| Hub Health | $398 | Included in subscription | Yes | First month discounted |
| Qoctor | $460 | $59.99 | e-script | e-script only |
| InstantScripts | $480 | $89 | Yes | Consult $89 |
| Juniper | $489 | $99 | Yes | Includes delivery |
Prices last checked 2026-04-03.
Annual cost estimate: $4,200–$6,000/year at maintenance dose.
Costs during the escalation phase are lower as you're on smaller doses. Some patients maintain weight loss at 10mg instead of 15mg, which also reduces cost.
How to get Mounjaro in Australia
Two routes: your GP or a telehealth provider. Both can prescribe Mounjaro if you meet the eligibility criteria (BMI ≥30, or ≥27 with comorbidity).
Telehealth providers often offer faster access with medication delivery to your door:
Compare providers for Mounjaro →
Mounjaro vs Wegovy
The two most common alternatives. Mounjaro produces more weight loss (~21% vs ~15-17%) and has lower nausea rates. Wegovy has stronger cardiovascular data (SELECT trial) and a pending PBS listing. Both cost $350–500/month privately.