Key points
- Tirzepatide acts on two gut hormones (GIP and GLP-1); semaglutide acts on one (GLP-1).
- In a head-to-head trial, people lost about 20% of their body weight on tirzepatide and about 14% on semaglutide over 72 weeks.
- Semaglutide costs less, and generic versions have been available in India since March 2026.
- Side effects are similar for both: mostly stomach-related, mostly while the dose goes up.
At a glance
| Mounjaro | Wegovy | Ozempic | |
|---|---|---|---|
| Medicine | Tirzepatide | Semaglutide | Semaglutide |
| How it works | Acts on two gut hormones, GIP and GLP-1 | Acts on GLP-1 | Acts on GLP-1 |
| Licensed for | Type 2 diabetes and weight management | Weight management | Type 2 diabetes |
| How it's taken | Weekly injection | Weekly injection | Weekly injection |
| Strengths in India | 2.5 mg to 15 mg | 0.25 mg to 2.4 mg | 0.25 mg to 1 mg |
| Average weight loss in its main trial | 20.9% over 72 weeks at 15 mg | About 15% over 68 weeks | Studied for blood sugar control |
| Price per month (MRP, Oct 2026) | ₹13,125 to ₹25,781 | ₹5,660 to ₹16,400 | ₹5,660 to ₹9,100 |
| Generic version in India | No | Generic semaglutide, from March 2026 | Generic semaglutide, from March 2026 |
* Prices are manufacturers' maximum retail prices (MRP) in India, checked October 2026, and are shown as a guide only. Prices change often and may differ when you buy. Lean Life does not sell medicines online: any medicine is prescribed only after a consultation with a Lean Life doctor, and dispensed by a licensed pharmacy.
More on Ozempic in India and tablets vs injections.
How they work
Both medicines copy hormones your gut releases after eating. They slow how quickly your stomach empties and reduce hunger, so you feel full on less food. Semaglutide copies one hormone, GLP-1. Tirzepatide acts on GLP-1 and a second hormone, GIP, which is thought to explain part of its larger effect.
Which leads to more weight loss?
In separate trials, people on tirzepatide 15 mg lost 20.9% of their body weight on average over 72 weeks (SURMOUNT-1), and people on semaglutide 2.4 mg lost about 15% over 68 weeks (STEP 1).
The two have also been compared directly. In SURMOUNT-5, adults with obesity lost about 20% of their body weight on tirzepatide and about 14% on semaglutide over 72 weeks. These are averages: some people lose much more, some less.
Side effects
Both cause similar side effects, mainly nausea, diarrhoea, constipation and vomiting, mostly while the dose is being increased. In SURMOUNT-5, slightly more people stopped semaglutide because of stomach side effects than tirzepatide (5.6% vs 2.7%). Most serious risks are shared, with two differences: tirzepatide can make the contraceptive pill less reliable for a few weeks after starting and after each dose increase, and semaglutide carries a warning for people with diabetic eye disease. Read the full side effects guide.
Cost
Semaglutide is cheaper. At standard dose increases, the first four months cost about ₹70,781 for Mounjaro and about ₹35,610 for Wegovy at MRP. Generic semaglutide, available in India since March 2026, costs less again. Some generic products are approved only for type 2 diabetes, so your doctor will check which one fits. See the full cost guide.
What about Ozempic?
Ozempic contains the same medicine as Wegovy, semaglutide, but it is licensed for type 2 diabetes and is sold in India only up to 1 mg. Rybelsus is semaglutide as a daily tablet, also licensed for type 2 diabetes. For weight management, doctors in India usually prescribe Wegovy, Mounjaro or a generic semaglutide approved for weight management.
Which one is right for you?
There's no single answer. Your doctor will weigh up:
- How much weight you want to lose, and your health goals
- Your budget, and whether a generic is suitable
- Other conditions, such as type 2 diabetes or PCOS
- How you have coped with similar medicines before
- What's available at the time
Questions
Is Mounjaro stronger than Wegovy?
On average, people lost more weight on tirzepatide (Mounjaro) than on semaglutide (Wegovy), including in a head-to-head trial. That doesn't mean it's the better choice for everyone: cost, side effects and your health matter too.
Can I switch from semaglutide to Mounjaro?
Yes, under a doctor's supervision. Your doctor will decide the starting dose and how to step it up.
Is generic semaglutide as good as Wegovy?
Generics contain the same active medicine. Check that the product is approved in India for weight management, not only for diabetes, and that it comes from a licensed pharmacy.
Which has fewer side effects?
Rates of stomach side effects were broadly similar in the trials. How you personally react is hard to predict, which is why both start at a low dose.
References
- Jastreboff AM et al. Tirzepatide once weekly for the treatment of obesity (SURMOUNT-1). N Engl J Med 2022
- Wilding JPH et al. Once-weekly semaglutide in adults with overweight or obesity (STEP 1). N Engl J Med 2021
- Aronne LJ et al. Tirzepatide as compared with semaglutide for the treatment of obesity (SURMOUNT-5). N Engl J Med 2025
- Mounjaro summary of product characteristics, European Medicines Agency
- Wegovy summary of product characteristics, European Medicines Agency
- World Health Organization. WHO issues global guideline on the use of GLP-1 medicines in treating obesity, 1 December 2025
- Indian maximum retail prices checked October 2026
