Quick Summary
Mounjaro (tirzepatide) and Trulicity (dulaglutide) are both manufactured by Eli Lilly and are FDA-approved once-weekly injections for type 2 diabetes. However, they differ fundamentally in mechanism: Mounjaro is a dual GIP/GLP-1 receptor agonist, while Trulicity is a GLP-1 receptor agonist only. This distinction in pharmacology translates into significant differences in clinical outcomes, with Mounjaro representing a newer and more potent approach to incretin-based therapy.
Clinical trial data indicates that Mounjaro delivers substantially greater HbA1c reduction and weight loss than Trulicity. In the SURPASS program, tirzepatide at its highest dose (15 mg) achieved HbA1c reductions of approximately 2.0% or greater and weight loss of roughly 10-12 kg in type 2 diabetes populations. Trulicity (dulaglutide 1.5 mg) has typically achieved HbA1c reductions of approximately 1.3-1.5% and more modest weight loss in its AWARD trial program. While cross-trial comparisons carry inherent limitations, the magnitude of these differences is notable. The SURPASS-5 trial, which included insulin-treated patients, reinforced tirzepatide's strong glycemic and weight effects.
Both medications share gastrointestinal side effects common to the GLP-1 class, including nausea, diarrhea, and decreased appetite. Trulicity has a longer track record of post-market use and has demonstrated cardiovascular benefit in the REWIND trial. Mounjaro's cardiovascular outcomes data is still being evaluated. Cost, insurance coverage, and formulary placement often differ between the two despite sharing a manufacturer. Patients currently on Trulicity who are interested in Mounjaro should discuss the potential benefits and risks of switching with their healthcare provider.
Mounjaro vs Trulicity: Full Comparison
| Feature | Mounjaro(tirzepatide) | Trulicity(dulaglutide) |
|---|---|---|
| Active Ingredient | tirzepatide | dulaglutide |
| Drug Class | Dual GIP and GLP-1 receptor agonist | GLP-1 receptor agonist |
| Manufacturer | Eli Lilly | Eli Lilly |
| FDA Approved | 2022-05-13 | 2014-09-18 |
| Approved Indications |
|
|
| Route | subcutaneous injection | subcutaneous injection |
| Frequency | Once weekly | Once weekly |
| Starting Dose | 2.5 mg weekly | 0.75 mg weekly |
| Maintenance Dose | 5 mg, 10 mg, or 15 mg weekly | 1.5 mg weekly |
| Max Dose | 15 mg weekly | 4.5 mg weekly |
| Weight Loss (%) | 22.5% | 3.1% |
| A1C Reduction | 2.4% | 1.5% |
| Key Trial | SURMOUNT-1 (72 weeks) | REWIND (260 weeks) |
| List Price | $1,023-$1,176/month | $950-$1,100/month |
| With Insurance | $25-$150/month (varies by plan) | $25-$150/month (varies by plan) |
| Savings Card | $25/month (Lilly savings card, commercially insured) | $25/month (Lilly savings card, commercially insured) |
Side Effects: Mounjaro vs Trulicity
| Side Effect | Mounjaro | Trulicity |
|---|---|---|
| Nausea | 12-18% | 12-21% |
| Diarrhea | 12-17% | 8-13% |
| Decreased appetite | 5-11% | 4-9% |
| Vomiting | 5-9% | 6-12% |
| Constipation | 6-7% | Not reported |
| Dyspepsia | 5-8% | 4-6% |
| Abdominal pain | 5-6% | 6-9% |
| Injection site reaction | 3-5% | Not reported |
| Pancreatitis (rare) | <0.5% | <0.5% |
| Fatigue | Not reported | 4-6% |
Severity scale: 1 (mild) to 5 (serious). Based on FDA prescribing information and clinical trial data.
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This content is for informational purposes only and is not medical advice. Always consult your healthcare provider before making medication decisions. See our full medical disclaimer.