Mounjaro is a type 2 diabetes medicine. Its label carries two indications, both in type 2 diabetes: blood-sugar control in adults and in children aged 10 and older, and lowering the risk of heart attack, stroke and cardiovascular death in adults at high risk. Weight management is a different brand of the same molecule, Zepbound. What the Mounjaro brand covers as a whole — its forms, when each use was added and how it relates to Zepbound — is on what is Mounjaro?. This page reads the trials behind the diabetes indications from the current prescribing information (Eli Lilly, DailyMed SPL version 40, effective 27 August 2026) and their ClinicalTrials.gov records, on 22 October 2026.
Five adult trials, five different comparators
The label's glycaemic evidence is five trials named SURPASS-1 to SURPASS-5. Each one put Mounjaro against something different, which is what makes the set worth reading together.
| Trial | Weeks | Randomised | Background therapy | Compared with | HbA1c change, Mounjaro 5 / 10 / 15 mg | HbA1c change, comparator | HbA1c <7%, Mounjaro vs comparator |
|---|---|---|---|---|---|---|---|
| SURPASS-1 | 40 | 478 | Diet and exercise only | Placebo | −1.8 / −1.7 / −1.7 | −0.1 | 82 / 85 / 78% vs 23% |
| SURPASS-2 | 40 | 1,879 | Metformin | Semaglutide 1 mg | −2.0 / −2.2 / −2.3 | −1.9 | 82 / 86 / 86% vs 79% |
| SURPASS-3 | 52 | 1,444 | Metformin ± SGLT2 inhibitor | Insulin degludec | −1.9 / −2.0 / −2.1 | −1.3 | 79 / 82 / 83% vs 58% |
| SURPASS-4 | 52 | 2,002 | 1–3 oral drugs, raised heart risk | Insulin glargine | −2.1 / −2.3 / −2.4 | −1.4 | 75 / 83 / 85% vs 49% |
| SURPASS-5 | 40 | 475 | Insulin glargine ± metformin | Placebo | −2.1 / −2.4 / −2.3 | −0.9 | 87 / 90 / 85% vs 35% |
HbA1c in percentage points, least-squares means, from baselines of 7.9% to 8.6%. Mounjaro prescribing information, sections 14.2–14.4, Tables 4–8; trial identifiers NCT03954834, NCT03987919, NCT03882970, NCT03730662 and NCT04039503.
Three patterns in that table are worth stating plainly:
- The doses barely separate. Within each trial the three Mounjaro doses land within 0.3 points of each other on HbA1c. In SURPASS-1 the 15 mg arm reached the 7% target least often of the three (78%). (glp1ledger reading of Tables 4–8.) The doses separate much more on body weight, which is where 10 mg and 15 mg pull away — that record is on Mounjaro for weight loss.
- Placebo did very different things in different settings. With no other diabetes drug (SURPASS-1), placebo moved HbA1c by 0.1 points and a quarter of that group needed rescue medication. Added to insulin that kept being adjusted (SURPASS-5), placebo fell by 0.9 — and the placebo group's glargine dose had risen to a mean of 59 units a day by week 40, against 29 to 38 units in the Mounjaro arms. A "difference from placebo" therefore depends on what the placebo group was already taking.
- The largest falls came from the trials with the highest starting HbA1c (SURPASS-4 and SURPASS-5, both around 8.3–8.6%). That is ordinary for diabetes trials and is why the five rows are not a ranking of settings.
The semaglutide comparison, and the dose that dates it
SURPASS-2 is the only trial on the label that compares Mounjaro with another GLP-1 drug. At 40 weeks every Mounjaro dose lowered HbA1c more than semaglutide 1 mg — by 0.2, 0.4 and 0.5 points — and more people reached an HbA1c below 7%.
The comparator dose is the limit. Semaglutide 1 mg was a standard Ozempic dose when the trial was designed; Ozempic is now approved at up to 2 mg a week, and no trial on either label compares Mounjaro with semaglutide 2 mg in diabetes. SURPASS-2 was also open-label with respect to which drug people received (only the Mounjaro dose was blinded). Both points narrow the finding rather than overturn it. Ozempic's own trial record is read the same way on Ozempic for type 2 diabetes, and the two brands set side by side, indication by indication, are on Mounjaro vs Ozempic.
The two insulin trials, and the titration behind them
Two of the five trials compared Mounjaro with long-acting insulin, and both are often summarised as "Mounjaro beat insulin". The label reports how far the insulin had been adjusted:
- SURPASS-4 (insulin glargine). Glargine started at 10 units a day and was adjusted weekly toward a fasting glucose under 100 mg/dL. The label states that at week 52 "30% of patients randomized to insulin glargine achieved the fasting serum glucose target of <100 mg/dL, and the mean daily insulin glargine dose was 44 U (0.5 U per kilogram)."
- SURPASS-3 (insulin degludec) was open-label, and the label reports the degludec group's HbA1c fall (1.3 points) without a comparable statement of how many reached target.
So in the glargine trial, seven in ten people on insulin had not reached the protocol's own fasting-glucose goal by the primary endpoint. That does not erase the difference — a 52-week trial with a treat-to-target algorithm is a fair test of what insulin does in practice, where under-titration is common — but it means the result compares Mounjaro with insulin as it was adjusted in that protocol, not with insulin at a reached target. The label's own wording is "compared with insulin glargine once daily", and the caveat sits one paragraph above it. Weight moved in opposite directions: up 1.7 to 1.9 kg on the insulins, down on every Mounjaro dose. How tirzepatide and insulin differ as drug types is on is GLP-1 insulin?.
Children aged 10 and older
SURPASS-PEDS (NCT05260021) randomised 99 patients aged 10 to 17, already on metformin, basal insulin or both, to Mounjaro 5 mg, 10 mg or placebo for 30 weeks, followed by a 22-week open-label extension. The patients' mean age was 15, 61% were female, mean diabetes duration 2.4 years and mean BMI 35.
| Week 30 | Placebo (34) | Mounjaro 5 mg (32) | Mounjaro 10 mg (33) | 5 and 10 mg pooled (65) |
|---|---|---|---|---|
| HbA1c change (points) | −0.2 | −1.9 | −2.2 | −2.0 |
| HbA1c ≤6.5% | 28% | 68% | 81% | 75% |
| BMI change | −0.5% | −6.9% | −10.8% | −8.8% |
Mounjaro prescribing information, section 14.5, Table 9.
Two limits come with it: the trial is small (65 children on the drug), and the adult maximum of 15 mg was not tested — the paediatric label stops at 10 mg. The heart-risk indication does not extend to children. How the GLP-1 drugs are labelled for younger patients across the class is on GLP-1 drugs for teens.
The heart indication: what SURPASS-CVOT measured
SURPASS-CVOT (NCT04255433) randomised 13,299 adults with type 2 diabetes and established cardiovascular disease to Mounjaro (up to 15 mg) or dulaglutide 1.5 mg — Trulicity, a GLP-1 drug that already held a heart indication — and followed them for a median of 210.1 weeks.
| Outcome | Dulaglutide (6,647) | Mounjaro (6,647) | Hazard ratio (95% CI) |
|---|---|---|---|
| CV death, non-fatal heart attack or non-fatal stroke | 863 (13.0%) | 803 (12.1%) | 0.92 (0.83–1.01) |
| Cardiovascular death | 409 (6.2%) | 367 (5.5%) | 0.89 (0.77–1.02) |
| Non-fatal heart attack | 310 (4.7%) | 292 (4.4%) | 0.93 (0.80–1.09) |
| Non-fatal stroke | 221 (3.3%) | 215 (3.2%) | 0.97 (0.80–1.16) |
| All-cause death | 670 (10.1%) | 567 (8.5%) | 0.84 (0.75–0.94) |
Mounjaro prescribing information, section 14.6, Table 10. The primary outcome's interval is a 95.3% confidence interval; the component and all-cause rows are "not controlled for family-wise type I error rate", in the label's words.
The trial was designed to show Mounjaro was not worse than dulaglutide, and it did (p = 0.007 for non-inferiority). The label then says it directly: "Superiority to dulaglutide was not established." Every component's interval crosses 1. The all-cause death result is the one row whose interval stays below 1, and it is exactly the kind of secondary finding the label flags as uncontrolled for multiple testing — worth reporting, not a proven effect.
Because the comparator was an active heart-protective drug rather than placebo, the trial cannot say how much Mounjaro reduces cardiovascular risk compared with no GLP-1 treatment. Why that makes Mounjaro's heart claim a different kind of claim from Ozempic's, and why the indication's population ("at high risk") is wider than the trial's (established disease), is set out on Mounjaro vs Ozempic.
What this record does not establish
- No trial on the label compares Mounjaro with semaglutide at current maximum diabetes doses, or with any SGLT2 inhibitor as the randomised comparator (SGLT2 inhibitors appear only as background therapy).
- No kidney-outcome trial supports a kidney indication. Mounjaro has none; Ozempic's FLOW-based kidney indication has no Mounjaro counterpart on the label.
- HbA1c is a surrogate. The five glycaemic trials ran 40 to 52 weeks; the only long-term outcome evidence is SURPASS-CVOT, and it was against an active comparator.
- The label's safety record sits with the side-effect pages: gastrointestinal effects, low blood sugar when combined with insulin or a sulfonylurea, and the thyroid C-cell boxed warning are tabled on Mounjaro side effects.
Getting it for diabetes
Insurers treat a type 2 diabetes prescription differently from a weight-management one, and Mounjaro's savings card terms are written around the diabetes indication; both are covered, dated, on Mounjaro cost, the Mounjaro savings card page and GLP-1 insurance coverage.
This page reports the label and the trial registry. It is not advice on whether Mounjaro suits any person's diabetes; that decision belongs with the prescriber, who can weigh the trial record against the person's other medicines and history.
Sources
- Eli Lilly and Company, MOUNJARO (tirzepatide) injection and MOUNJARO KwikPen, prescribing information, DailyMed set ID d2d7da5d-ad07-4228-955f-cf7e355c8cc0, SPL version 40, effective 2026-08-27 — sections 1, 2, 14.1–14.6 (Tables 4–10), dailymed.nlm.nih.gov, read 22 October 2026.
- ClinicalTrials.gov records NCT03954834 (SURPASS-1), NCT03987919 (SURPASS-2), NCT03882970 (SURPASS-3), NCT03730662 (SURPASS-4), NCT04039503 (SURPASS-5), NCT05260021 (SURPASS-PEDS) and NCT04255433 (SURPASS-CVOT), as cited in the label, read 22 October 2026.