Mounjaro adds a pediatric indication and a Severe Gastrointestinal Adverse Reactions warning

Eli Lilly's Mounjaro (tirzepatide) picked up two notable labeling changes dated December 2025: the type 2 diabetes indication was extended to children 10 years of age and older, and a new Warnings and Precautions subsection on severe gastrointestinal adverse reactions was added ^[1][2].

The indication now reads that Mounjaro is 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" ^[2]. Dosing sections 2.1 and 2.2 were revised the same month ^[2].

What the dosing change says

The escalation schedule is the same for adults and children: 2.5 mg injected under the skin once weekly to start, increasing to 5 mg once weekly after 4 weeks, then in 2.5 mg increments after at least 4 weeks on the current dose if more glycemic control is needed ^[2]. The label states the 2.5 mg starting dose "is for treatment initiation and is not intended for glycemic control," and says the step-up schedule is meant to reduce the risk of gastrointestinal side effects ^[2].

The ceiling is where adults and children differ. The maximum dosage is 15 mg once weekly in adults and 10 mg once weekly in pediatric patients ^[1][2]. The label also keeps its missed-dose language: a missed dose can be taken within 4 days (96 hours), and if more than 4 days have passed, the dose is skipped, with at least 3 days (72 hours) between doses when the weekly day is changed ^[2].

The pediatric evidence appears in a clinical studies subsection covering Mounjaro used with metformin or basal insulin, or both, in patients 10 years and older with type 2 diabetes ^[2]. The trial's size, duration and A1C results are not included in the source text reviewed here, so those numbers are not yet known from this material.

The new gastrointestinal warning

Section 5.6, Severe Gastrointestinal Adverse Reactions, now states that use "has been associated with gastrointestinal adverse reactions, sometimes severe," and that "MOUNJARO is not recommended in patients with severe gastroparesis" ^[1][2]. Gastroparesis means the stomach empties too slowly.

That sits alongside existing warnings for acute pancreatitis, hypoglycemia when combined with insulin or insulin secretagogues, serious hypersensitivity reactions, acute kidney injury from volume depletion, diabetic retinopathy complications, acute gallbladder disease, and pulmonary aspiration during general anesthesia or deep sedation ^[1][2]. The boxed warning about thyroid C-cell tumors in rats remains, as does the contraindication in people with a personal or family history of medullary thyroid carcinoma or Multiple Endocrine Neoplasia syndrome type 2 ^[1][2].

The most common adverse reactions, reported in 5% or more of patients, are nausea, diarrhea, decreased appetite, vomiting, constipation, indigestion and abdominal pain ^[1][2]. The label also notes that tirzepatide delays stomach emptying and can affect how other oral medicines are absorbed ^[1][2].

Why it matters for patients

For families, the practical change is that a once-weekly GIP/GLP-1 receptor agonist is now formally labeled for type 2 diabetes in kids as young as 10, with a lower maximum dose than adults get ^[1][2]. Insurance coverage often follows FDA-approved labeling, so an on-label pediatric use can matter for access, though the sources do not address coverage.

The 5.6 warning gives prescribers explicit label language about digestive risk rather than leaving it in the side-effect tables. People with severe gastroparesis now have a named, labeled reason the drug is not recommended for them ^[1][2]. Why FDA and Lilly added the subsection in December 2025 is not stated in these documents.

What happens next

The label kept moving after December 2025. Administration instructions (2.2) and a new warning against sharing a KwikPen between patients (5.10) are dated 01/2026, and an indication to reduce the risk of major adverse cardiovascular events in adults with type 2 diabetes at high risk, plus updates to recommended dosage (2.1) and the diabetic retinopathy warning (5.7), are dated 08/2026 ^[1]. The posted label was revised 8/2026 ^[1].