Semaglutide vs. Tirzepatide: Evidence, Differences and Cost

Tirzepatide produced greater average weight loss than semaglutide in a direct trial of particular weekly injections. That result does not make it the best choice for every person or establish how every current formulation compares. Product, health history, tolerability, access and ongoing cost all belong in the decision.

Here is what to compare before your appointment. US product information was checked on October 8, 2026.

First, match the ingredient to the product

Question	Semaglutide	Tirzepatide
Which receptors does it act on?	GLP-1	GIP and GLP-1
Main weight-management brand	Wegovy	Zepbound
Forms of that brand	Weekly injection; daily tablet	Weekly injection
A diabetes brand using the ingredient	Ozempic	Mounjaro

The first three rows follow the Wegovy and Zepbound labels. Ozempic and Mounjaro have type 2 diabetes indications; sharing an ingredient does not make brand labels interchangeable.

Both pathways are involved in metabolic signaling. Receptor names explain how the medicines differ, but counting receptors does not predict how much weight an individual will lose. Start with the clinical evidence for the product being considered.

What the direct weight-loss trial found

SURMOUNT-5 randomized 751 adults with obesity and without type 2 diabetes to weekly injections for 72 weeks. It was open-label and funded by Eli Lilly. Participants received the maximum tolerated study dose. Primary trial

Trial arm	Doses studied	Estimated average change in body weight at week 72
Tirzepatide	10 or 15 mg weekly	−20.2% (95% CI: −21.4% to −19.1%)
Semaglutide	1.7 or 2.4 mg weekly	−13.7% (95% CI: −14.9% to −12.6%)

The estimates differed by 6.5 percentage points. These are group results, not a forecast or dosing recommendation. Gastrointestinal adverse events were most common in both groups, usually mild or moderate and concentrated during dose escalation. SURMOUNT-5 results

What those numbers do not answer

The trial did not compare oral semaglutide or the newer 7.2 mg Wegovy HD injection. Both tablets and that higher injectable strength appear in the current Wegovy label. Do not use the table to claim that tirzepatide beats every semaglutide option now available.

Another direct trial, SURPASS-2, studied adults with type 2 diabetes over 40 weeks. It compared tirzepatide with semaglutide 1 mg weekly, with blood-glucose control as its primary endpoint. That is a different question from the obesity trial above. SURPASS-2 publication

Direct comparisons study groups under the same protocol. Comparisons assembled from separate trials bring extra differences in participants, follow-up and analysis. Check which kind of evidence a headline is using.

Practical differences worth discussing

Your daily routine. A pill may feel easier than an injection, but oral Wegovy has fasting and timing instructions. Bring your normal morning schedule and other medicines to the discussion. The product label explains administration requirements; your pharmacist can help you understand them.

Other health goals. Product indications differ. For example, Wegovy injection has a cardiovascular risk-reduction indication in adults with established cardiovascular disease and overweight or obesity, while Zepbound has an indication for moderate-to-severe obstructive sleep apnea in adults with obesity. Ask how any relevant condition affects the choice. FDA Wegovy announcement, Zepbound label

Safety and other medicines. Both labels include a thyroid C-cell tumor boxed warning and contraindications involving medullary thyroid carcinoma and MEN2. Your clinician also needs to assess gastrointestinal problems, pregnancy plans and medication interactions. Zepbound specifically advises additional or alternative contraception for people using oral hormonal contraceptives for four weeks after starting and after each dose increase. Wegovy safety information, Zepbound safety information

Compare the treatment plan and the bill

Ask each provider for a written quote covering the same period and the same exact product. Separate medication from membership, appointments, shipping and any required testing. Record when an introductory offer ends and what changes if insurance denies coverage.

Then ask what support the price buys. Who responds to side effects? How are progress and tolerability reviewed? What happens if the medicine is unavailable or the plan becomes unaffordable? Our GLP-1 cost worksheet helps keep those questions together.

NIDDK identifies cost, expected benefit, adverse effects, medical history and other medicines as factors in choosing treatment. A medicine’s average trial performance is only one part of that conversation. NIDDK decision guidance

Questions to take to your clinician

• Which product and formulation fit my health goals, and why?
• Does the comparison you are using match that product and someone like me?
• What would count as a useful response, and when will we review it?
• What should I do if symptoms interfere with meals, work or daily life?
• Can I sustain the full cost and the care routine?

Save the appointment checklist, or inspect the semaglutide and tirzepatide entries in the field guide. A good comparison should leave you better prepared to discuss your options, without pushing you to change treatment yourself.

Sources and further reading

1. Aronne et al.: SURMOUNT-5 direct comparison, NEJM 2025 (opens in a new tab)
2. Frías et al.: SURPASS-2 in type 2 diabetes, NEJM 2021 (opens in a new tab)
3. Wegovy prescribing information, revised June 2026 (opens in a new tab)
4. FDA: Wegovy cardiovascular indication, March 2024 (opens in a new tab)
5. Zepbound prescribing information, revised August 2026 (opens in a new tab)
6. Ozempic prescribing information (opens in a new tab)
7. Mounjaro prescribing information (opens in a new tab)
8. NIDDK: Choosing and continuing weight-management medication (opens in a new tab)

Sources checked October 8, 2026. Prices, labels and policies can change. Linked studies being peer reviewed does not mean this article has been clinically reviewed.