Mounjaro (tirzepatide) and Trulicity (dulaglutide) are both once-weekly injectable medications approved to treat type 2 diabetes, but they work differently. Trulicity is a GLP-1 receptor agonist, mimicking one gut hormone to help release insulin and slow digestion. Mounjaro is a dual GIP/GLP-1 receptor agonist — the first drug to mimic two incretin hormones at once — which is associated with larger reductions in blood sugar and body weight in head-to-head data.
What Is Mounjaro?
Mounjaro is the brand name for tirzepatide, a once-weekly self-injected medication approved by the FDA to treat type 2 diabetes in adults and children ages 10 and older. It’s the first medication approved that activates both GIP (glucose-dependent insulinotropic polypeptide) and GLP-1 (glucagon-like peptide-1) receptors. In August 2026, the FDA also approved Mounjaro to lower the risk of major cardiovascular events — heart attack, stroke, and cardiovascular death — in adults with type 2 diabetes at high cardiovascular risk, based on results from the SURPASS-CVOT trial.
What Is Trulicity?
Trulicity is the brand name for dulaglutide, a once-weekly self-injected GLP-1 receptor agonist approved for type 2 diabetes in adults and children 10 and older. Trulicity also carries an additional FDA-approved indication to reduce the risk of major cardiovascular events in adults with type 2 diabetes who already have cardiovascular disease or multiple cardiovascular risk factors.
Mounjaro vs Trulicity: Dosing
| Mounjaro (tirzepatide) | Trulicity (dulaglutide) | |
|---|---|---|
| Starting dose | 2.5 mg weekly | 0.75 mg weekly |
| Maximum dose | 15 mg weekly | 4.5 mg weekly |
| Dose escalation | Every 4 weeks | Can start at a therapeutic 1.5 mg dose |
Efficacy: Blood Sugar and Weight
In clinical trials, dulaglutide (Trulicity) reduced HbA1c by about 1–1.5 percentage points, with modest weight loss of roughly 2–6 pounds over 26 weeks. Tirzepatide (Mounjaro), because it targets two incretin pathways instead of one, produced larger reductions — HbA1c drops of roughly 1.5–2.4 percentage points and average weight loss of about 15–22 pounds at higher doses in trial data. Individual results vary significantly, and these figures come from clinical trial averages, not guarantees for any one patient.
Side Effects
Both drugs share a similar side effect profile since they work through related hormone pathways. The most common side effects for both are gastrointestinal: nausea, vomiting, and diarrhea, especially during the first weeks of treatment or after a dose increase. Gastrointestinal side effects are reported somewhat more often with Mounjaro (around 20–30% of users) than Trulicity (around 10–20%), likely reflecting its dual mechanism and larger effect size.
Both drugs carry a boxed warning about a risk of thyroid C-cell tumors seen in rodent studies, and neither should be used by anyone with a personal or family history of medullary thyroid carcinoma or Multiple Endocrine Neoplasia syndrome type 2. Both are also associated with a risk of pancreatitis. This is general information, not medical advice — anyone considering either medication should discuss their personal risk factors with a prescriber.
Frequently Asked Questions
Is Mounjaro stronger than Trulicity?
In head-to-head efficacy data, Mounjaro produced greater reductions in both blood sugar and body weight than Trulicity, largely because it acts on two incretin hormone receptors instead of one. “Stronger” also means a higher likelihood of GI side effects, so the right choice depends on an individual’s health profile, not just relative potency.
Are Mounjaro and Trulicity taken the same way?
Yes — both are self-administered as a once-weekly subcutaneous injection, typically in the abdomen, thigh, or upper arm, using a prefilled pen.
Can you switch from Trulicity to Mounjaro?
Switching between the two is a decision made with a prescriber, who will set an appropriate starting dose for Mounjaro rather than simply matching the previous Trulicity dose, since the two drugs aren’t dosed on a 1:1 equivalent basis.
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