Head-to-head comparison
| Property | Tirzepatide | Dulaglutide |
|---|---|---|
| Category | Weight Loss | Weight Loss |
| Legal Status | Prescription | Prescription |
| Primary Route | subcutaneous | subcutaneous |
| Half-life | ~5 days | ~90 hours (~5 days) |
| Mol. Weight | 4,813.45 Da | 59,669 Da |
| Side Effects | Nausea (up to 31%), Diarrhea, Vomiting | Nausea (most common, typically resolves within weeks), Diarrhea, Vomiting |
Key differences
- Receptor targets: Tirzepatide is a dual GIP/GLP-1 receptor agonist; dulaglutide is a GLP-1 receptor agonist only.
- Weight loss: SURPASS head-to-head data showed tirzepatide (15 mg) produced significantly more weight loss than dulaglutide (1.5 mg); tirzepatide achieves 22.5% in obesity trials vs dulaglutide's approximately 4.7% in diabetes trials.
- HbA1c reduction: Tirzepatide demonstrates superior HbA1c lowering compared to dulaglutide in SURPASS trials.
- Both are weekly injections: Both tirzepatide and dulaglutide are administered once weekly via subcutaneous injection.
- Manufacturer: Both are Eli Lilly products. Dulaglutide (Trulicity) was approved in 2014; tirzepatide (Mounjaro) in 2022.
- Indications: Dulaglutide is approved for type 2 diabetes with cardiovascular outcomes data (REWIND trial); tirzepatide is approved for both diabetes and obesity.
- Cardiovascular data: Dulaglutide has published CV outcomes data (REWIND trial showing reduced MACE); tirzepatide CV outcomes trials are ongoing.
The verdict
Tirzepatide is the clearly superior option for both weight loss and glycemic control based on head-to-head data. However, dulaglutide has the advantage of longer market experience, established cardiovascular outcomes data (REWIND), and broader insurance coverage in some markets. As tirzepatide accumulates long-term safety data and CVOT results, dulaglutide's remaining advantages will narrow. Both are Eli Lilly products, with tirzepatide positioned as the next-generation replacement.
Frequently asked questions
Head-to-head SURPASS trial data shows tirzepatide produces superior HbA1c reduction and significantly more weight loss than dulaglutide. Tirzepatide's dual GIP/GLP-1 mechanism provides benefits beyond what dulaglutide's GLP-1-only mechanism achieves.
This is a physician decision based on individual health profile, insurance coverage, and treatment goals. Clinical data supports tirzepatide's superiority for both glycemic control and weight loss. Switching requires medical guidance for dose titration.
Yes, the REWIND trial demonstrated that dulaglutide reduced major adverse cardiovascular events (MACE) in patients with type 2 diabetes. This is a current advantage over tirzepatide, whose cardiovascular outcomes trials are still ongoing.
Yes, both are once-weekly subcutaneous injections. This is a shared convenience advantage. The key difference is efficacy — tirzepatide produces substantially more weight loss and HbA1c reduction due to its additional GIP receptor activity.
Eli Lilly developed dulaglutide as its first-generation GLP-1 agonist and subsequently developed tirzepatide as a next-generation dual agonist. This is a typical pharmaceutical pipeline pattern where newer compounds improve upon earlier products from the same company.