Mounjaro is the brand name for tirzepatide, a once-weekly injectable medication FDA-approved to improve blood sugar control in adults with type 2 diabetes and to reduce the risk of major cardiovascular events in adults with type 2 diabetes and known heart disease. It is a GLP-1 receptor agonist that works by increasing insulin secretion, decreasing glucagon secretion, and slowing gastric emptying.

Is Mounjaro approved for weight loss?

Mounjaro is FDA-approved only for type 2 diabetes, not for weight loss. However, a higher-dose formulation of the same active ingredient (tirzepatide) is marketed as Wegovy and is FDA-approved specifically for chronic weight management. While Mounjaro can cause weight loss as a side effect (average 12-14 pounds in clinical trials), using it off-label for weight loss should only be done under medical supervision.

How much does Mounjaro cost?

Without insurance, Mounjaro typically costs $900-$1,000 per month. With insurance, copays vary widely from $25 to $300+ depending on your plan. Novo Nordisk offers a savings card that may reduce copays to $25 for up to 24 months for eligible commercially insured patients. Medicare and Medicaid coverage varies by plan and state.

What are the most common side effects?

The most common side effects are gastrointestinal: nausea (15-20% of patients), diarrhea (9%), vomiting (9%), constipation (5%), and abdominal pain (6%). These typically improve over time. Serious but rare risks include pancreatitis, gallbladder problems, kidney injury, diabetic retinopathy complications, and thyroid tumors (seen in animal studies, not yet confirmed in humans).

Mounjaro (Tirzepatide) — Diabetes & Weight Loss Information

⚠️ Important Safety Information

Boxed Warning: Thyroid C-cell tumors have been observed in animal studies. Mounjaro is contraindicated in patients with a personal or family history of medullary thyroid carcinoma (MTC) or in patients with Multiple Endocrine Neoplasia syndrome type 2 (MEN 2). Consult your healthcare provider about your risk.

Overview

What is Mounjaro?

Mounjaro (tirzepatide) is a GLP-1 receptor agonist that mimics the action of glucagon-like peptide-1, a hormone that regulates blood sugar and appetite. It is FDA-approved for two indications:

1. Type 2 Diabetes: To improve blood sugar control in adults with type 2 diabetes, in combination with diet and exercise.

2. Cardiovascular Risk Reduction: To reduce the risk of major adverse cardiovascular events (heart attack, stroke, cardiovascular death) in adults with type 2 diabetes and established cardiovascular disease.

Not FDA-approved for weight loss. Wegovy (same active ingredient, higher dose) is the FDA-approved formulation for chronic weight management.

Comparison

How does Mounjaro compare to other GLP-1 medications?

Medication	Active Ingredient	Frequency	Average A1C Reduction	Average Weight Loss
Mounjaro	Tirzepatide	Once weekly	1.5% (2 mg dose)	12-14 lbs
Mounjaro	Tirzepatide	Once weekly	2.0-2.5% (15 mg dose)	15-25 lbs
Trulicity	Dulaglutide	Once weekly	1.0-1.5%	4-8 lbs
Victoza	Liraglutide	Daily	1.0-1.5%	6-10 lbs

Data from respective FDA labels and head-to-head clinical trials. Individual results vary.

Mechanism

How does Mounjaro work?

Tirzepatide is a GLP-1 receptor agonist that works through three primary mechanisms:

1. Increases insulin secretion: Stimulates the pancreas to release insulin in response to elevated blood sugar (glucose-dependent, so lower risk of hypoglycemia when used alone).

2. Decreases glucagon secretion: Reduces the release of glucagon, a hormone that raises blood sugar, helping prevent glucose spikes.

3. Slows gastric emptying: Delays the movement of food from the stomach to the intestines, which slows the absorption of glucose and increases feelings of fullness.

These combined effects result in improved blood sugar control and, as a side effect, weight loss.

Clinical Evidence

What do the clinical trials show?

Mounjaro has been studied in the SUSTAIN clinical trial program involving over 8,000 patients with type 2 diabetes:

SUSTAIN 6 (Cardiovascular Outcomes): Demonstrated a 26% reduction in major adverse cardiovascular events (MACE) including cardiovascular death, nonfatal heart attack, and nonfatal stroke compared to placebo. Published in New England Journal of Medicine, 2016.

SUSTAIN 1-5 & 7 (Glycemic Control): Showed A1C reductions ranging from 1.0% to 1.8% depending on dose and baseline A1C. Weight loss ranged from 8-14 pounds on average over 30-56 weeks.

Common finding: Most patients experience nausea in the first 4-8 weeks, which typically improves over time. Gradual dose escalation helps minimize gastrointestinal side effects.

Important Considerations

What should I discuss with my doctor?

Mounjaro is a prescription medication that requires medical supervision. Before starting, discuss:

Your complete medical history, especially any history of pancreatitis, kidney disease, diabetic retinopathy, or thyroid cancer
All medications you're taking, especially insulin or sulfonylureas (increased hypoglycemia risk when combined)
Whether you're pregnant, planning to become pregnant, or breastfeeding
Your insurance coverage and whether you qualify for manufacturer savings programs
Realistic expectations for blood sugar control and weight loss

This is not medical advice. Only your healthcare provider can determine if Mounjaro is appropriate for you.

Mounjaro (Tirzepatide) for Type 2 Diabetes