If you have been handed a Mounjaro pen or you are reviewing the drug before starting it, the single most authoritative document is the FDA-approved prescribing information, also called the package insert or product label. It is the legal reference that defines exactly who Mounjaro (tirzepatide) is approved for, how it should be dosed, what its boxed warning says, and which side effects were seen in clinical trials. This guide translates the current Mounjaro prescribing information into plain language, pulls the real numbers straight from the FDA label revised January 2026, and walks through the approval history so you can see how the drug reached its current status.[1]
🔑 Key Takeaways
- Mounjaro (tirzepatide) is FDA approved only as an adjunct to diet and exercise to improve glycemic control in adults and pediatric patients 10 years of age and older with type 2 diabetes. It is not FDA approved for weight loss; that indication belongs to its sister product, Zepbound.[1]
- The package insert carries a boxed warning for the risk of thyroid C-cell tumors. Mounjaro is contraindicated in anyone with a personal or family history of medullary thyroid carcinoma (MTC) or Multiple Endocrine Neoplasia syndrome type 2 (MEN 2).[1]
- The label dose schedule starts at 2.5 mg once weekly, increases to 5 mg after 4 weeks, then rises in 2.5 mg steps no sooner than every 4 weeks, to a maximum of 15 mg weekly for adults and 10 mg weekly for children 10 and older.[1]
- The most common adverse reactions in the prescribing information are gastrointestinal: nausea, diarrhea, decreased appetite, vomiting, constipation, dyspepsia, and abdominal pain.[1]
- The 2026 label reflects two expansions since first approval: the December 2025 addition of pediatric patients 10 and older, and the multi-dose vial presentations alongside the original single-dose pens and vials.[1][8]
What Is the Mounjaro Prescribing Information?
The prescribing information is the FDA-regulated document that accompanies every approved medication. It opens with a section called Highlights of Prescribing Information, a one or two page summary that physicians can read quickly, followed by the Full Prescribing Information with numbered sections covering indications, dosage, contraindications, warnings, adverse reactions, drug interactions, use in specific populations, clinical pharmacology, and clinical studies. The same content, formatted for the public, is published on DailyMed by the National Library of Medicine.[2]
For Mounjaro, the official label is published by Eli Lilly and reviewed by the FDA. The version current as of this writing was revised January 2026 (reference ID on the FDA document) and is the source for the dosing, warnings, and adverse-event figures cited throughout this article.[1] If you want the manufacturer-facing consumer overview rather than the regulatory document, our Mounjaro uses, dosage and cost guide covers the same drug from a practical standpoint, while Mounjaro medication overview summarizes the day-to-day basics.
Mounjaro FDA Approved Indications
According to the indications and usage section of the label, Mounjaro is a glucose-dependent insulinotropic polypeptide (GIP) receptor and glucagon-like peptide-1 (GLP-1) receptor agonist indicated as an adjunct to diet and exercise to improve glycemic control in adults and pediatric patients 10 years of age and older with type 2 diabetes mellitus.[1] Type 2 diabetes is a chronic condition in which the body does not use insulin properly, leading to elevated blood glucose, and it affects roughly one in ten U.S. adults.[3]
Mounjaro is not the same as Zepbound, even though both are tirzepatide. Mounjaro is approved only for type 2 diabetes. The identical molecule is marketed as Zepbound for chronic weight management and obstructive sleep apnea. The FDA approves drugs by indication, so the brand name on the box tells you which approved use it was prescribed under, not what the drug can chemically do.[4]
It is worth being precise about what the label does and does not say. The Mounjaro package insert does not list weight loss, prediabetes, or cardiovascular risk reduction as approved indications, even though tirzepatide produces substantial weight loss and has cardiovascular outcome data. Weight loss with tirzepatide is the basis for the separate Zepbound approval. For a full breakdown of how the two brands compare, see our Zepbound vs Mounjaro comparison.
Boxed Warning and Contraindications
The most prominent safety element of any label is the boxed warning, the strongest warning the FDA can require. Mounjaro's boxed warning reads, in summary, that tirzepatide causes thyroid C-cell tumors in rats, and it is unknown whether Mounjaro causes thyroid C-cell tumors, including medullary thyroid carcinoma (MTC), in humans because the human relevance of the rodent finding has not been determined. The label states that Mounjaro is contraindicated in patients with a personal or family history of MTC or in patients with MEN 2, and that patients should be counseled about the symptoms of thyroid tumors.[1]
Beyond the thyroid contraindication, the contraindications section also lists known serious hypersensitivity to tirzepatide or any of the excipients in Mounjaro.[1]
Dosage and Administration From the Label
The dosage and administration section gives a precise titration schedule designed to limit gastrointestinal side effects. The recommended starting dosage is 2.5 mg injected subcutaneously once weekly. After 4 weeks, the dose increases to 5 mg once weekly. If additional glycemic control is needed, the dose is increased in 2.5 mg increments after at least 4 weeks on the current dose. The maximum dosage is 15 mg once weekly for adults and 10 mg once weekly for pediatric patients 10 years of age and older.[1]
| Step | Dose (once weekly) | Time on this dose before next step | Purpose per label |
|---|---|---|---|
| Starting dose | 2.5 mg (2,500 mcg) | 4 weeks | Initiation, not for glycemic control |
| Step 2 | 5 mg (5,000 mcg) | At least 4 weeks | First therapeutic dose |
| Step 3 | 7.5 mg | At least 4 weeks | If more glycemic control needed |
| Step 4 | 10 mg | At least 4 weeks (pediatric maximum) | If more glycemic control needed |
| Step 5 | 12.5 mg | At least 4 weeks | If more glycemic control needed |
| Maximum | 15 mg (adults only) | Maintenance | Adult maximum dose |
On administration, the label specifies that Mounjaro is injected subcutaneously into the abdomen, thigh, or the back of the upper arm (the upper-arm site should be injected by another person), at any time of day, with or without meals, and that injection sites should be rotated with each dose.[1] For a hands-on walkthrough of pen technique and site rotation, see our Mounjaro injection guide, and for how the dose schedule translates into weeks and expected timelines, our tirzepatide dosing guide goes deeper.
Dosage Forms and Strengths
The dosage forms and strengths section of the package insert lists two delivery formats. The original presentations are single-dose pens and single-dose vials at 2.5, 5, 7.5, 10, 12.5, or 15 mg per 0.5 mL. The label also lists multi-dose vials, each containing four weekly doses, at strengths of 10 mg/2.4 mL (four 2.5 mg doses), 20 mg/2.4 mL (four 5 mg doses), 30 mg/2.4 mL (four 7.5 mg doses), 40 mg/2.4 mL (four 10 mg doses), 50 mg/2.4 mL (four 12.5 mg doses), and 60 mg/2.4 mL (four 15 mg doses).[1]
Warnings and Precautions
The warnings and precautions section is where most of the day-to-day clinical caution lives. The Mounjaro label lists nine numbered items.[1]
- Risk of thyroid C-cell tumors (5.1): the basis for the boxed warning.
- Acute pancreatitis (5.2): reported with GLP-1 receptor agonists and Mounjaro; discontinue if pancreatitis is suspected.
- Hypoglycemia with insulin secretagogues or insulin (5.3): combining Mounjaro with a sulfonylurea or insulin can raise the risk of low blood sugar; a dose reduction of the other drug may be needed.
- Hypersensitivity reactions (5.4): serious reactions including anaphylaxis and angioedema have been reported.
- Acute kidney injury due to volume depletion (5.5): usually tied to dehydration from nausea, vomiting, or diarrhea.
- Severe gastrointestinal adverse reactions (5.6): Mounjaro is not recommended in patients with severe gastroparesis.
- Diabetic retinopathy complications (5.7): monitor patients with a history of diabetic retinopathy.
- Acute gallbladder disease (5.8): gallbladder problems including gallstones occurred in trials.
- Pulmonary aspiration during general anesthesia or deep sedation (5.9): because the drug slows stomach emptying, patients should tell providers about any planned surgery or procedure.
Adverse Reactions: The Real Numbers
The adverse reactions section summarizes what happened in the controlled trials. The most common adverse reactions reported in at least 5 percent of patients treated with Mounjaro were nausea, diarrhea, decreased appetite, vomiting, constipation, dyspepsia, and abdominal pain.[1] The table below shows the placebo-controlled, dose-by-dose incidence from the adult monotherapy data in the label, illustrating that gastrointestinal effects rise with dose and are largely concentrated during titration.
| Adverse reaction | Placebo | Mounjaro 5 mg | Mounjaro 10 mg | Mounjaro 15 mg |
|---|---|---|---|---|
| Nausea | 4% | 12% | 15% | 18% |
| Diarrhea | 9% | 12% | 13% | 17% |
| Decreased appetite | 1% | 5% | 10% | 11% |
| Vomiting | 2% | 5% | 5% | 9% |
| Constipation | 1% | 6% | 6% | 7% |
| Dyspepsia | 3% | 8% | 8% | 5% |
The label notes that the majority of reports of nausea, vomiting, and diarrhea occurred during dose escalation and decreased over time.[1] For a deeper, management-focused breakdown, our tirzepatide side effects guide covers what to do about each one.
How Mounjaro Works (Clinical Pharmacology)
The mechanism of action section describes tirzepatide as a GIP receptor and GLP-1 receptor agonist. It is a peptide with a C20 fatty diacid that enables albumin binding and prolongs the half-life, which is approximately 5 days, allowing once-weekly dosing. Tirzepatide selectively binds to and activates both the GIP and GLP-1 receptors, enhances first and second-phase insulin secretion, and reduces glucagon, both in a glucose-dependent manner.[1] This dual-agonist design is what distinguishes tirzepatide from single GLP-1 drugs; the broader science is covered in our how Mounjaro works explainer and in independent pharmacology references.[5]
Mounjaro FDA Approval History Timeline
Reading the label tells you the current status; the approval history tells you how it got there. Below is a synthesized timeline drawn from FDA documents, the manufacturer, and peer-reviewed trial publications.
| Date | Milestone | What it means |
|---|---|---|
| May 13, 2022 | Initial U.S. approval for adult type 2 diabetes | First FDA-approved drug to target both GIP and GLP-1 receptors.[6] |
| June 2021 (data) | SURPASS-2 published in NEJM | 15 mg cut A1C by 2.46% and body weight by 12.4 kg (about 27 lb), beating semaglutide 1 mg in a head-to-head trial.[7] |
| 2024 to 2025 | Multi-dose vials added; aspiration and severe-GI warnings added | New presentations and label safety updates (warnings 5.6 and 5.9 added 11/2024).[1] |
| July 31, 2025 | SURPASS-CVOT cardiovascular results announced | In over 13,000 adults with type 2 diabetes and established cardiovascular disease, tirzepatide met non-inferiority versus dulaglutide for major adverse cardiovascular events.[8] |
| December 2025 | Pediatric expansion to ages 10 and older | Mounjaro became the second GLP-1-class drug approved for pediatric type 2 diabetes; pediatric maximum is 10 mg weekly.[1][8] |
The cardiovascular dataset deserves a note because it is frequently misread. In SURPASS-CVOT, three-point major adverse cardiovascular events occurred in 12.2 percent of the tirzepatide group versus 13.1 percent of the dulaglutide group over a median 4 years, with a hazard ratio of 0.92, meeting the prespecified non-inferiority criterion; all-cause mortality was numerically lower with tirzepatide.[8] Importantly, this trial compared tirzepatide against another active GLP-1 drug rather than placebo, and cardiovascular risk reduction is still not a labeled indication for Mounjaro.[1]
Why the trial numbers do not always match the label numbers. Trials like SURPASS-2 report large weight and A1C effects, but a drug label only lists outcomes for the conditions it is approved to treat. Mounjaro's label centers on glycemic control because that is its indication. The same molecule's weight-loss numbers appear on the Zepbound label instead. When you read prescribing information, the indication frames everything that follows.[1][4]
Use in Specific Populations
The use in specific populations section flags several groups. Based on animal studies, Mounjaro may cause fetal harm and is generally avoided in pregnancy. Because tirzepatide can reduce the effectiveness of oral contraceptives by delaying gastric emptying, the label advises women using oral birth control to switch to a non-oral method or add a barrier method for 4 weeks after starting and for 4 weeks after each dose increase.[1] The label also addresses geriatric, renal, and hepatic use; no dose adjustment is specified for kidney or liver impairment, but monitoring is advised.[1]
Drug Interactions
The drug interactions section is short but practical. Because Mounjaro delays gastric emptying, it can affect the absorption of oral medications taken at the same time. The most clinically emphasized example is oral contraceptives, addressed above. Patients taking oral drugs with a narrow therapeutic window should discuss timing with their prescriber.[1]
Where to Read the Official Documents
You do not have to take any third party's word for the label. The primary documents are public. The Highlights and Full Prescribing Information PDF is hosted at the FDA's Drugs@FDA document repository.[1] The same content in a public-friendly layout, including the Medication Guide, is on DailyMed.[2] The FDA Drug Trials Snapshot summarizes who the drug was tested in and the headline efficacy and safety findings.[6] If you are comparing Mounjaro against the rest of the class before a conversation with your doctor, our GLP-1 drugs compared overview puts the labeled options side by side.
Frequently Asked Questions
References
- MOUNJARO (tirzepatide) injection, Full Prescribing Information, U.S. Food and Drug Administration, revised January 2026.
- Mounjaro (tirzepatide) label, DailyMed, U.S. National Library of Medicine.
- Type 2 Diabetes, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), NIH.
- FDA Approves New Medication for Chronic Weight Management (Zepbound, tirzepatide), U.S. Food and Drug Administration.
- Farzam K, Patel P. Tirzepatide. StatPearls, NCBI Bookshelf.
- Drug Trials Snapshots: MOUNJARO, U.S. Food and Drug Administration.
- Frias JP, et al. Tirzepatide versus Semaglutide Once Weekly in Patients with Type 2 Diabetes (SURPASS-2). N Engl J Med. 2021. PMID 34170647.
- SURPASS-CVOT: Tirzepatide versus Dulaglutide in T2D and ASCVD, American College of Cardiology journal scan.