Tirzepatide vs semaglutide: what the head-to-head trial shows, and what it means in India

Semaglutide acts on one gut-hormone receptor, GLP-1, while tirzepatide acts on two, GIP and GLP-1, and each comes as a weekly injection under its US label^10,11.

"US label" rows come from the US prescribing labels on DailyMed; "India" rows come from Indian reports, filings, a pharmacy listing and the records of CDSCO, India's drug regulator^8,10,12.

Our semaglutide dose schedule sets out each step, and the tablets are compared in GLP-1 tablets and oral semaglutide in India.

Tirzepatide gave more weight loss on average: 20.2 % against 13.7 % for semaglutide at 72 weeks, in 751 adults¹. Their average BMI (body-mass index) was 39². Each took the highest dose they could tolerate¹.

SURMOUNT-5 assigned people to each medicine at random, and Eli Lilly funded it¹. NEJM Journal Watch, a summary service for doctors, says the maker of tirzepatide ran it as an open-label comparison, in which doctors and patients knew who took which medicine^2,21.

Three weight-loss trials, all in adults without diabetes, from their PubMed abstracts; placebo groups had dummy injections^1,22,23.

The head-to-head trial's results record on ClinicalTrials.gov, a US trial registry, gives one region of enrolment for everyone in its baseline table: the United States³. It records 18 of them as Asian, a US race category³. In June 2026, a CDSCO expert committee said obesity and overweight are defined differently for US and Asian populations²⁴.

In STEP 1, 50.5 % of people on semaglutide 2.4 mg lost 15 % or more of their weight, so the rest lost less²². At the lower mark, 86.4 % lost at least 5 %, against 31.5 % on placebo²². In SURMOUNT-1, 57 % of people on tirzepatide 15 mg and 50 % on 10 mg lost 20 % or more, against 3 % on placebo²³. The rest lost less²³.

In SURMOUNT-1, tirzepatide 5 mg gave −15.0 % at 72 weeks, against −20.9 % on 15 mg²³. With diabetes, the averages were lower^22,23,25,26. In STEP 2, adults with type 2 diabetes lost 9.6 % on semaglutide 2.4 mg at 68 weeks²⁵. In SURMOUNT-2, the figures were 12.8 % on tirzepatide 10 mg and 14.7 % on 15 mg at 72 weeks²⁶.

These results took 68 to 72 weeks^1,22. Under the US Wegovy label the long-term (maintenance) dose starts only in week 17, and in SURMOUNT-1 the 72 weeks included 20 weeks of dose increases^10,23. In India, each Mounjaro KwikPen holds four weekly doses¹⁶.

In both US labels' trials, everyone was told to eat about 500 kcal a day less and to be active for at least 150 minutes a week^10,11. On that advice and a placebo injection, people lost 2.4 % in STEP 1 and 3.1 % in SURMOUNT-1^22,23.

A year after people in the STEP 1 extension stopped semaglutide 2.4 mg and the lifestyle programme, they had regained, on average, two-thirds of the weight they had lost²⁷. In SURMOUNT-4, adults who completed the first 36 weeks on tirzepatide had lost 20.9 % on average²⁸. At week 88, those then switched to placebo were 9.9 % below their starting weight on average, against 25.3 % for those kept on tirzepatide²⁸. The authors call this a substantial regain of lost weight²⁸. The two trials had different designs, so their figures do not compare directly.

In the head-to-head trial, digestive side effects were the most common with both medicines; most were mild to moderate in severity and came mainly during the dose increases¹. Vomiting was less common on tirzepatide, at 15 % against 21 %³. The trial record lists serious adverse events in 4.8 % of people on tirzepatide and 3.5 % on semaglutide, with no deaths³. In each group, 6 people left the trial because of an adverse event³.

Non-serious side effects in SURMOUNT-5, which had no placebo group, from its results on ClinicalTrials.gov³.

From the US labels of Wegovy and Zepbound (tirzepatide's US weight-loss brand). Separate trials with separate placebo groups. Not a head-to-head comparison^10,11.

Read each against its own placebo. Placebo nausea was 16 % in the semaglutide trials and 8 % in the tirzepatide trials, so the two medicine columns cannot be set side by side^10,11. On the US labels, nausea looks less common with tirzepatide (25–29 %) than with semaglutide 2.4 mg (44 %)^10,11. Head to head, both groups had 44 %³.

Tell the doctor who prescribed your medicine about any side effect that bothers you. For common side effects of semaglutide, the UK's National Health Service (NHS) advises staying on the medicine unless told to stop²⁹.

When to call 112, and other serious warnings

• Call 112 at once for a swollen throat or tongue, a raised itchy rash or difficulty breathing^29,30,31. These can be signs of a serious allergic reaction, which the NHS lists for both medicines^29,30. Call 112 too if someone may have very low blood sugar and is not responding normally or is unconscious^31,32. Give an unconscious person no food or drink³².
• Stop the medicine and contact a doctor immediately for severe, lasting stomach pain that may reach the back, a possible sign of pancreatitis, as an NHS diabetes leaflet advises³³. Both US labels warn about acute pancreatitis, and the US tirzepatide label says to stop it if pancreatitis is suspected^10,11.
• Contact your doctor straight away for pain in the upper stomach, yellow skin or eyes, fever or clay-coloured stools^10,11. The US Medication Guides of both medicines link these to gallbladder problems, and the NHS lists gallstones among the serious side effects of tirzepatide^10,11,30.
• Treat low blood sugar quickly if you have diabetes and feel sweaty, shaky or dizzy, or your heart pounds^29,30,32. The NHS advises eating or drinking something that raises blood sugar quickly, such as a small glass of fruit juice³². Then tell your doctor.
• Tell your doctor about a lump in the neck, trouble swallowing, shortness of breath or a hoarse voice that does not go away^10,11. Both US labels list these as signs of a thyroid tumour^10,11.

Both US labels carry a boxed warning on thyroid C-cell tumours, which each medicine caused in rodents; whether this happens in people is not known^10,11. Medullary thyroid cancer starts in these C cells³⁴. Under the US labels, neither medicine may be used by someone with a personal or family history of it, or with MEN 2^10,11. MEN 2 (multiple endocrine neoplasia type 2) is a genetic condition³⁵. Suspected side effects can also be reported to India's Pharmacovigilance Programme (PvPI) on its helpline, 1800 180 3024, on working days from 9:00 am to 5:30 pm^36,37. Other signs that need help, for both medicines, are in our guide to GLP-1 side effects.

Of the two, only semaglutide has generics in India^5,7.

Semaglutide. Novo Nordisk launched Wegovy in India on 24 June 2025, and Emcure sells a second Wegovy brand, Poviztra, under a November 2025 agreement with Novo Nordisk^13,14. The patent expired on 20 March 2026, and news reports listed generic brands from Indian companies that month^5,6. In the CDSCO committee minutes we read, most generic approvals were for type 2 diabetes, and some brands were reported for weight management too³⁸. Generic brand names are listed in GLP-1 medicines in India: brands and generics.

Tirzepatide. Lilly launched Mounjaro in India on 20 March 2025, for weight management and for type 2 diabetes, according to a PTI report at the launch^15,39. Cipla launched Yurpeak, a second tirzepatide brand made by Lilly, on 11 December 2025⁴.

Prescription rules. PharmEasy, an online pharmacy, lists Mounjaro and Wegovy as Schedule H medicines that are not sold over the counter^8,9. A health-ministry release of 24 March 2026 says GLP-1 weight-loss drugs were approved on condition of prescription by endocrinologists and internal medicine specialists, and, for some uses, by cardiologists⁴⁰. A news summary reported a March 2026 government warning that generic semaglutide must be sold only on a registered medical practitioner's prescription⁴¹.

Suspected fake pens. In April 2026, Haryana's drug regulator was reported to have seized more than 260 suspected counterfeit Mounjaro pens⁴². The NHS warns that some websites sell fake weight-loss medicines, and it advises using a registered pharmacy³⁰.

Cost. Compare dose with dose. At the starting dose, Wegovy 0.25 mg was priced at ₹1,415 a week from 1 April 2026, BioSpectrum India reported⁴³. On 1 October 2026, PharmEasy listed the Mounjaro 2.5 mg KwikPen at an MRP of ₹13,125 for a pen of four weekly doses^8,16. At the top dose, Novo Nordisk India's price table, as reported in March 2026, set Wegovy 2.4 mg at ₹4,100 a week (₹16,400 a month) from 1 April 2026⁴⁴. On the same PharmEasy listing, Mounjaro 12.5 mg and 15 mg pens were ₹25,781 each, and Cipla said in October 2025 that it would match Mounjaro's price for Yurpeak^8,45. A review in the journal Diabetes Care, reported by The South First on 24 September 2026, put generic semaglutide at ₹2,000 to ₹3,500 a month, depending on the maker⁴⁶. The report names no dose⁴⁶.

Prices as reported on the dates above; sources read by 21 October 2026.

This page recommends neither medicine. A doctor weighs these questions with you.

• Do you have type 2 diabetes? Launch reports say Mounjaro came to India for diabetes as well as weight, and semaglutide is sold here for diabetes as Ozempic^39,47. Both medicines' diabetes trials showed lower average weight loss^25,26. Both US labels warn that use with insulin or a sulfonylurea may raise the risk of low blood sugar^10,11.
• Where does your BMI sit? A government backgrounder defines obesity in India as a BMI of 25 or more⁴⁸. PTI reported that Mounjaro's Indian launch covered a BMI of 30 or more, or 27 or more with a weight-related condition³⁹. In 2026, a CDSCO committee kept BMI cut-offs in tirzepatide's approved use²⁴. CDSCO records show Wegovy approved in India for chronic weight management in adults, and its launch report gave no BMI cut-offs^12,13.
• Have you or a close relative had medullary thyroid cancer, or do you have MEN 2? Both US labels rule out these medicines in that case^10,11. Other reasons not to start are covered in who should not take a GLP-1 medicine.
• Do you take the contraceptive pill? The US Zepbound label says tirzepatide may make the pill less effective¹¹. It advises a non-oral method, or an added barrier method for 4 weeks after starting and after each dose increase¹¹.
• Are you planning a pregnancy? The NHS advises stopping semaglutide at least 2 months before trying, and tirzepatide at least 4 weeks before^29,30.
• Can you continue, and pay, for many months? Weight returned after treatment stopped in both medicines' trials^27,28.

Tablets and other medicines are compared in which GLP-1 is best for weight loss. Talk to a Zelta specialist to go through these questions with a doctor.

Is semaglutide better or worse than tirzepatide? For average weight loss, tirzepatide did better in SURMOUNT-5, a randomised, open-label trial enrolled in the US and run by tirzepatide's maker^1,2,3. The most common side effects with both were digestive¹. Choose with a doctor.

How much weight can you lose on tirzepatide in three months? The trials report their results at 72 weeks, not at three months^1,23. In the early months the dose is still rising: under its US label, tirzepatide starts at 2.5 mg for 4 weeks and goes up in 2.5 mg steps¹¹. No trial average is a promise for one person.

Is semaglutide the generic of Ozempic? Semaglutide is the medicine's own (generic) name, and Ozempic and Wegovy are Novo Nordisk's brand names for it^13,49. A generic medicine is the same medicine made by another company, and in India such semaglutide brands have been on sale since the patent expired on 20 March 2026^5,6.

Is there a generic tirzepatide in India? No. Bloomberg reported that tirzepatide was still under patent protection in India in April 2026, and both brands sold here, Mounjaro and Cipla's Yurpeak, are made by Lilly^4,7,15.