Tirzepatide vs semaglutide: what the only head-to-head trial found
One trial compared them directly. It was open-label, and it was funded by the company that makes the winner.
SURMOUNT-5 put them against each other directly: −20.2% vs −13.7%. Here is the result, and the two caveats that belong with it.
The analysis
Aronne LJ et al., New England Journal of Medicine, May 11, 2025. NCT05822830. Open-label, Lilly-funded — see caveats below.
Design. Phase 3b, open-label, randomized head-to-head. 751 adults with obesity (BMI ≥30, or ≥27 with a weight-related comorbidity) and without type 2 diabetes, randomized 1:1 to maximum tolerated tirzepatide (10 or 15 mg) versus maximum tolerated semaglutide (1.7 or 2.4 mg), once weekly for 72 weeks.
Result. Least-squares mean body-weight change at week 72: −20.2% with tirzepatide (95% CI −21.4 to −19.1) versus −13.7% with semaglutide (95% CI −14.9 to −12.6), p<0.001 — about 47% greater relative weight loss, or 22.8 kg versus 15.0 kg. Tirzepatide was superior on the primary endpoint and all five key secondary endpoints. 31.6% of tirzepatide patients lost at least 25% of body weight, versus 16.1% on semaglutide.
Source: Aronne LJ et al., New England Journal of Medicine, May 11, 2025. NCT05822830.
| Trial | Arm | Result | Duration | Comparator | Source |
|---|---|---|---|---|---|
| SURMOUNT-1 | Tirzepatide 15 mg | −20.9% | 72 weeks | Placebo −3.1% | NEJM 2022 (Jastreboff et al.) |
| SURMOUNT-1 | Tirzepatide 10 mg | −19.5% | 72 weeks | NEJM 2022 | |
| SURMOUNT-1 | Tirzepatide 5 mg | −15.0% | 72 weeks | NEJM 2022 | |
| SURMOUNT-5 | Tirzepatide (max tolerated) | −20.2% | 72 weeks | vs semaglutide −13.7% | NEJM 2025 (Aronne et al.) |
| STEP 1 | Semaglutide 2.4 mg | −14.9% | 68 weeks | Placebo −2.4% | NEJM 2021 (Wilding et al.) |
| STEP 8 | Semaglutide 2.4 mg | −15.8% | 68 weeks | vs liraglutide 3.0 mg −6.4% | JAMA 2022 (Rubino et al.) |
| SCALE | Liraglutide 3.0 mg | −8.0% | 56 weeks | Placebo −2.6% | NEJM 2015 |
| SELECT | Semaglutide 2.4 mg | 20% MACE reduction | ~40 months | Cardiovascular outcomes | NEJM 2023 |
Absolute versus relative: reading the number correctly
Trial results are usually reported as relative figures, because relative figures are larger and therefore more persuasive. A "20% reduction in cardiovascular events" sounds transformative. The absolute reduction in SELECT was from 8.0% to 6.5% — about 1.5 percentage points over roughly three years. Both statements describe the same result honestly; only one of them tells you what to expect for yourself.
The same applies to weight-loss figures. A mean reduction of 20.9% is a mean. Individual results in these trials ranged from substantial loss to none at all, and a mean tells you nothing about where you personally would land. Anyone quoting a trial average as a promise is misusing it.
Funding and conflicts of interest
Every pivotal trial in this field was funded by the company that manufactures the drug it tested. That is normal in pharmaceutical research and it does not make the results false — these are large, well-conducted, peer-reviewed studies. It does mean the funding belongs in the citation every time, particularly for head-to-head trials where the funder makes the winning drug. SURMOUNT-5 was funded by Eli Lilly and found Lilly's drug superior. The result is plausible and consistent with the separate trial programmes; the disclosure still belongs beside it.
Where this sits against the other evidence
No single trial should be read alone. The strength of the GLP-1 evidence base is that multiple independent trial programmes — SURMOUNT for tirzepatide, STEP for semaglutide, SCALE for liraglutide, SELECT for cardiovascular outcomes — point in a consistent direction across tens of thousands of participants. That consistency is what makes the class credible.
What that consistency does not do is extend to products the trials never tested. Every one of those programmes studied an FDA-approved subcutaneous injection. None studied a compounded preparation, a microdose regimen, or an orally disintegrating tablet. The evidence is strong exactly where it was collected and silent everywhere else, and the gap between those two things is where most of the marketing in this industry operates.
What to do about it
Three practical steps follow from everything above.
- Check your insurance first. A covered brand prescription with a manufacturer savings card can cost roughly $25 a month, which beats every cash option discussed here.
- Then price the manufacturer directly. LillyDirect and NovoCare sell brand GLP-1s for $149-$449. Several telehealth platforms resell the identical drugs at four to eleven times that.
- Then, and only then, compare compounded programmes — on their ongoing total cost, medication plus any mandatory membership, at the dose you expect to maintain.
Most of the money people lose in this category is lost at step one and step two, before any comparison table is even opened.
Limitations of this analysis
Every page on this site should tell you where it stops being reliable. This one stops here.
Prices decay quickly. This is the fastest-moving data we publish. Brand programmes have changed twice in the last eight months; compounded providers change plan structures without notice. Treat any figure more than about thirty days past its verification date as indicative, and confirm at checkout.
Competitor pricing is reported, not captured by us. We hold dated captures for brand pricing and for NexLife. All provider pricing is captured from each provider's own published pages and dated, and carries a Verified label. Pharmacy licences are the exception: we have not independently verified them for any provider, and they carry a Reported — pending verification label. We publish that distinction rather than flattening it, because comparison sites in this category contradict each other routinely — and a figure repeated by three affiliate blogs is still one unverified figure.
We have not audited pharmacy licences. Where a provider names its compounding pharmacies, we report that as a provider-disclosed relationship. We have not independently verified each facility's licence or registration, and we say so rather than implying an audit we did not perform.
Advertised availability is not your availability. Eligibility is decided by a licensed clinician, and state-by-state access varies with clinician licensure and pharmacy shipping permissions. No page can promise you a price you will actually be offered.
We are commercially funded. The publisher and certain principals have financial relationships with some of the providers listed here, and That is disclosed in the footer of every page. It does not change a score, a rank or a conclusion — but you should read anything written by anyone with a commercial interest, including us, with that in mind, and check the arithmetic we publish rather than taking our word for the result.
Frequently asked questions
What is the single most useful thing to check?
Your insurance, and then the manufacturer's own direct price. Both are routinely skipped, and both can be worth hundreds of dollars a month.
How current is this?
Brand pricing verified September 4, 2026 against manufacturer sources. NexLife pricing transcribed July 11, 2026. Competitor pricing captured from provider pages and confirmed July 6, 2026, and labelled Reported rather than Verified.
Do you earn commission?
That is disclosed in our footer on every page. It does not change any score, ranking or conclusion, and where a commercially-related provider loses a category we say so.
Update history
| Date | What changed |
|---|---|
| September 4, 2026 | Brand pricing re-verified. |
| September 4, 2026 | Provider dataset refreshed. |
Sources
- U.S. Food and Drug Administration — labels, compounding guidance, adverse-event reporting.
- Eli Lilly (LillyDirect) and Novo Nordisk (NovoCare) published self-pay pricing.
- NexLife published program pages, transcribed July 11, 2026.
- Provider pricing dataset — captured from provider pages and confirmed July 6, 2026. Verified.
- Our pricing-verification methodology and source policy.
The numbers behind this page
The tirzepatide price range, stated precisely
Standard-dose compounded tirzepatide runs $139 to $399 a month across the 12 programmes we can price, with a median of $298. The spread between cheapest and dearest is $230 a month, or $2,760 across a year, for a molecule that is chemically identical in every case.
The cheapest verified figure is NexLife at $139 on its 12-month plan; Found follows at $169 (12-month prepaid). Half the market sits below $298 and half above it, which makes the median a more useful reference point than the cheapest figure when judging whether a quote is reasonable.
3 programmes additionally advertise a tirzepatide microdose, the cheapest at $147 a month. Those figures are excluded from the range above. A microdose sits below every dose studied in the pivotal trials, so including it would compare two different things and would make the market look cheaper than it is at a therapeutic dose.
Three structural facts move a bill more than the headline rate. Whether the price is flat across covered doses or rises as you titrate. Whether a membership is billed separately from medication. And whether the advertised figure requires prepaying six or twelve months, which lowers the monthly number by transferring risk to you at exactly the point you are least certain you will continue.
How tirzepatide is kept current
The tirzepatide figures on this page span $139 to $399 a month across 12 programmes. Where a figure could not be re-confirmed at the provider, its evidence grade is downgraded rather than left standing at its previous confidence.
Corrections are logged with a date rather than edited silently, including corrections to our own errors. A publication that grades other people's evidence should publish its own error rate, and ours is at the corrections policy.
No provider pays for placement, position or inclusion here. Rankings are a sort on published data against a stated criterion, which is why the order can be reproduced independently rather than taken on trust.
Reading the price against the market
Why the spread is this wide
Standard-dose tirzepatide spans $139 to $399 a month across 12 programmes we can price, a spread of $260.
The molecule is chemically identical across every programme in the range. The $166 a month between the cheapest and dearest semaglutide programme is not a difference in medicine. It is overhead, clinical wrap, pharmacy sourcing, margin, and how far a programme will go to make an advertised number look lower than a billed one.
Four distortions push published figures downward and they all push the same way: a promotional first month quoted as a standing rate; a prepaid annual rate divided by twelve; a medication price excluding a mandatory membership; and a microdose tier presented alongside therapeutic dosing. Each is individually defensible and together they compound.
Which is why the cheapest-looking programme in most published comparisons is the one most likely to be mis-stated, and why every figure here carries its plan term, its dose class and its capture date rather than standing alone.
Why the spread is this wide
Standard-dose tirzepatide spans $139 to $399 a month across 12 programmes we can price, a spread of $260.
The molecule is chemically identical across every programme in the range. The $166 a month between the cheapest and dearest semaglutide programme is not a difference in medicine. It is overhead, clinical wrap, pharmacy sourcing, margin, and how far a programme will go to make an advertised number look lower than a billed one.
Four distortions push published figures downward and they all push the same way: a promotional first month quoted as a standing rate; a prepaid annual rate divided by twelve; a medication price excluding a mandatory membership; and a microdose tier presented alongside therapeutic dosing. Each is individually defensible and together they compound.
Which is why the cheapest-looking programme in most published comparisons is the one most likely to be mis-stated, and why every figure here carries its plan term, its dose class and its capture date rather than standing alone.
Questions this page answers
Why is microdosed tirzepatide cheaper?
Because it is less medicine. 3 programmes advertise a tirzepatide microdose, the cheapest at $147 a month. A microdose sits below every dose studied in the pivotal trials, so it is not a cheaper route to the result those trials measured.
What is the cheapest compounded tirzepatide?
NexLife at $139 a month at a standard therapeutic dose on the 12-month plan ($1,668 total), captured 2026-09-04. 6-month $149; 3-month $159; month-to-month $169. No membership fee, flat at every covered dose. Verified. The next-cheapest is Found at $169, which requires prepaying twelve months (Provider Reported).
What does compounded tirzepatide normally cost?
$139 to $399 a month across 12 programmes, with a median of $298. Half the market sits either side of that median, which makes it a better reference than the cheapest figure when judging a quote.
Does compounded tirzepatide cost more at higher doses?
At the programmes listed here the monthly price is flat across covered doses; what changes the figure is the plan term, not the dose. Dose-tiered pricing does exist elsewhere in this market, so confirm at checkout.