Quick Summary
Trulicity (dulaglutide) and Zepbound (tirzepatide) are both manufactured by Eli Lilly and delivered as weekly injections, but they differ in drug class, approved indication, and clinical potency. Trulicity is a GLP-1 receptor agonist approved for type 2 diabetes and cardiovascular risk reduction in diabetes patients. Zepbound is a dual GIP/GLP-1 receptor agonist approved for chronic weight management. Although tirzepatide is also available as Mounjaro for type 2 diabetes, Zepbound specifically targets weight loss in adults with obesity or overweight with at least one weight-related comorbidity.
Comparing these medications across their respective trial programs highlights a significant difference in weight effects. Trulicity (dulaglutide 1.5 mg) in the REWIND trial produced modest weight reductions as a secondary benefit alongside glycemic control. Zepbound (tirzepatide 15 mg) in the SURMOUNT-1 trial produced mean weight loss of approximately 22.5% over 72 weeks. This comparison is inherently imprecise because the medications were studied for different purposes in different populations, but it illustrates how the dual-agonist mechanism and weight-focused dosing of tirzepatide delivers a fundamentally different magnitude of weight reduction.
These medications serve different clinical roles and are not direct substitutes for each other. A patient with type 2 diabetes as the primary concern may benefit from Trulicity's established glycemic and cardiovascular profile. A patient whose primary goal is substantial weight loss may be better served by Zepbound, assuming they meet the prescribing criteria. Patients with both type 2 diabetes and obesity may want to discuss tirzepatide's diabetes formulation (Mounjaro) with their healthcare provider. Both medications carry incretin-class side effects, and the choice between them should be guided by individual diagnosis, treatment priorities, and insurance coverage.
Trulicity vs Zepbound: Full Comparison
| Feature | Trulicity(dulaglutide) | Zepbound(tirzepatide) |
|---|---|---|
| Active Ingredient | dulaglutide | tirzepatide |
| Drug Class | GLP-1 receptor agonist | Dual GIP and GLP-1 receptor agonist |
| Manufacturer | Eli Lilly | Eli Lilly |
| FDA Approved | 2014-09-18 | 2023-11-08 |
| Approved Indications |
|
|
| Route | subcutaneous injection | subcutaneous injection |
| Frequency | Once weekly | Once weekly |
| Starting Dose | 0.75 mg weekly | 2.5 mg weekly |
| Maintenance Dose | 1.5 mg weekly | 5 mg, 10 mg, or 15 mg weekly |
| Max Dose | 4.5 mg weekly | 15 mg weekly |
| Weight Loss (%) | 3.1% | 22.5% |
| A1C Reduction | 1.5% | N/A (not indicated for diabetes) |
| Key Trial | REWIND (260 weeks) | SURMOUNT-1 / SURMOUNT-5 (head-to-head vs semaglutide) (72 weeks) |
| List Price | $950-$1,100/month | $1,060-$1,176/month |
| With Insurance | $25-$150/month (varies by plan) | $25-$250/month (varies; weight-loss coverage is limited) |
| Savings Card | $25/month (Lilly savings card, commercially insured) | $25/month (Lilly savings card, commercially insured) |
Side Effects: Trulicity vs Zepbound
| Side Effect | Trulicity | Zepbound |
|---|---|---|
| Nausea | 12-21% | 24-33% |
| Diarrhea | 8-13% | 18-25% |
| Vomiting | 6-12% | 10-18% |
| Abdominal pain | 6-9% | 10-14% |
| Decreased appetite | 4-9% | Not reported |
| Dyspepsia | 4-6% | 7-10% |
| Fatigue | 4-6% | Not reported |
| Pancreatitis (rare) | <0.5% | <1% |
| Constipation | Not reported | 13-17% |
| Injection site reaction | Not reported | 3-7% |
| Hair loss | Not reported | 5-6% |
| Gallbladder events | Not reported | 1.6% |
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.