Mounjaro is Eli Lilly's brand of tirzepatide for type 2 diabetes. It acts on two gut-hormone receptors at once, and it is the same molecule Lilly sells for weight as Zepbound. Its own label changed twice in the past ten months: it now covers children from age 10, and since 27 August 2026 it carries a heart-risk indication it did not have before.
Sources for everything below: Lilly's August 2026 Mounjaro label as posted on DailyMed, the NDA 215866 history and letters in Drugs@FDA, and the Orange Book's list of Mounjaro products — each checked on 5 October 2026.
Two approved uses, and when each arrived
| Approved use | Who | Added | FDA record |
|---|---|---|---|
| Lower blood sugar, alongside diet and exercise | adults with type 2 diabetes | 13 May 2022 | original approval |
| (extended) | children aged 10 and older with type 2 diabetes | 19 December 2025 | supplement 39 |
| Fewer cardiovascular deaths, heart attacks and strokes | adults with type 2 diabetes at high risk of those events | 27 August 2026 | supplement 44 |
Paraphrased from section 1 of the label; the approval letters supply each date and what it changed.
The paediatric extension rests on a trial FDA had required when it first approved the drug: the December 2025 letter says the 30-week placebo-controlled study with a 22-week open-label extension was run to meet a postmarketing requirement set in the May 2022 approval. The label reports that young patients' adverse reactions resembled adults' "with the exception of a higher incidence of vomiting, abdominal pain, and hypoglycemia".
The cardiovascular indication rests on SURPASS-CVOT: 13,299 people with diabetes who already had heart or vascular disease, randomised to Mounjaro or to dulaglutide (Trulicity), a GLP-1 drug that already held a heart indication. The same letter records that the trial's results also changed the label's diabetic-retinopathy warning, and that a second supplement approved the same day, supplement 45, revised the dosing section. The trial's result — non-inferior to dulaglutide, superiority not established — and how its population compares with the wording "at high risk" are on Mounjaro vs Ozempic. The safety findings are on Mounjaro side effects.
What the label does not cover: weight management, type 1 diabetes and children under 10. Weight is Zepbound's indication — and Zepbound gained no heart indication from the same trial, as what is Zepbound? records.
One molecule, two hormone receptors
Tirzepatide is a single peptide that switches on two receptors — those for GIP and for GLP-1, two hormones the gut releases after a meal. Its blood-sugar effect, per the label, comes from boosting both the early and the later phase of insulin release and from lowering glucagon, in each case only when glucose is raised.
Its backbone is GIP's, not GLP-1's. Two unusual amino acids (aminoisobutyric acid, at positions 2 and 13), an amidated end and a 20-carbon fatty acid hung from position 20 complete it; the fatty acid holds the drug to albumin, stretching its life to a week. It weighs 4,813.53 Da. What the two hormones do is on GIP and GLP-1; the molecule has an entry on Peptide Lexicon's tirzepatide page; and why none of this makes it a form of insulin is on the GLP-1-versus-insulin explainer.
Four forms, and when each arrived
| Form | Doses per unit | Listed by FDA |
|---|---|---|
| Single-dose pen (autoinjector) | 1 | 13 May 2022 |
| Single-dose vial | 1 | 28 July 2023 |
| Multi-dose vial | 4 | 7 January 2026 |
| KwikPen, single-patient-use | 4 | 20 January 2026 |
Orange Book product file dated 11 September 2026; each form at six strengths, 2.5 to 15 mg, for 24 listings in all. Doses per unit from section 3 of the August 2026 label.
The two four-dose forms are new this year and differ from the originals in more than count: the label lists preservatives in each multi-dose vial and KwikPen dose (benzyl alcohol 5.4 mg, phenol 1.08 mg) that the single-dose pen and vial do not contain, and the KwikPen "contains additional volume to allow for device priming". The same device under the Zepbound name is documented on the Zepbound KwikPen; storage rules for every pen are on GLP-1 pen storage. Strengths and schedules are reported on Peptifact's tirzepatide dosage page.
The same molecule as Zepbound: two labels, two age lines
Zepbound reached the market in November 2023 on its own application, for adult weight management, and later for obstructive sleep apnoea with obesity. The two brands therefore draw their lines differently: Mounjaro reaches down to age 10 but only for diabetes; Zepbound treats weight but only in adults. Because plans read the indication, a diabetes prescription for tirzepatide and a weight prescription for it can meet opposite coverage decisions; GLP-1 insurance coverage explains why, and the brands side by side on Mounjaro vs Zepbound. The label states that Mounjaro should not be combined with other tirzepatide products or with any GLP-1 receptor agonist.
Safety, briefly
The label opens with a boxed warning: tirzepatide caused thyroid C-cell tumours in rats, and whether it does so in people is unknown. Anyone with medullary thyroid cancer or MEN 2 in their own or family history, or a known serious allergy to the drug, is excluded. Seven gastrointestinal complaints each reached 5% of trial patients — nausea, diarrhoea, reduced appetite, vomiting, constipation, indigestion and abdominal pain — and the listed warnings run from pancreatitis and gallbladder disease to eye complications in people with existing retinopathy and inhaling stomach contents under anaesthesia. Trial rates for each are on Mounjaro side effects; applying them to one person is a prescriber's job.
Getting it, paying for it
A prescription is required. Prices are on what Mounjaro costs, the copay card's terms on the Mounjaro savings card, and Lilly's direct-to-patient service on LillyDirect. FDA's patent listings for Mounjaro run to 2036 for the compound and to 2041 for the latest-expiring patent; the detail is on when will tirzepatide go generic?
Sources
Mounjaro (tirzepatide) injection and Mounjaro KwikPen prescribing information, revised 08/2026, DailyMed set d2d7da5d-ad07-4228-955f-cf7e355c8cc0 · Drugs@FDA application record for NDA 215866 via openFDA · FDA approval letters for NDA 215866 supplement 39 (2025-12-19) and supplements 44 and 45 (2026-08-27) · FDA Orange Book product file dated 11 September 2026. All read 5 October 2026.