Mounjaro vs Trulicity for weight loss & A1C

On Trulicity vs Mounjaro, the head-to-head data favor Mounjaro. SURPASS-CVOT randomized 13,299 adults with type 2 diabetes and atherosclerotic heart disease to weekly tirzepatide up to 15 mg or dulaglutide 1.5 mg. At 36 months, A1C had fallen 1.66 points against 0.88, and body weight 11.6% against 4.8% (SURPASS-CVOT results).

Major heart events were close: 12.2% on Mounjaro and 13.1% on Trulicity in the NEJM report (12.1% and 13.0% in the label's count), which met the test for noninferiority but not superiority (NEJM, 2025). Trulicity was held at 1.5 mg, below its 4.5 mg top dose, and Eli Lilly, maker of both drugs, funded the trial. MedlinePlus keeps dulaglutide drug information for patients.

The difference between Trulicity and Mounjaro starts with the molecule. Trulicity is dulaglutide, which acts on the GLP-1 receptor. Mounjaro is tirzepatide, which acts on GLP-1 and a second receptor, GIP. Both are weekly shots approved for type 2 diabetes in adults and children 10 and older, and both carry a heart-risk indication. The earlier SURPASS trials are summarized in the post on tirzepatide vs dulaglutide for diabetes.

No trial has tested Trulicity vs Ozempic vs Mounjaro side by side, but two trials cover the pairs. In SUSTAIN 7, semaglutide 1 mg, the drug in Ozempic, lowered A1C 1.8 points against 1.4 for dulaglutide 1.5 mg over 40 weeks (Lancet Diabetes Endocrinol, 2018). In SURPASS-2, tirzepatide 15 mg lowered A1C 2.30 points against 1.86 for semaglutide 1 mg (NEJM, 2021). The ADA's 2026 Standards of Care rank tirzepatide and semaglutide highest for glucose lowering and weight loss, followed by dulaglutide (ADA, 2026).

Scroll the table sideways to see both columns →

Mounjaro vs Trulicity comes down to mechanism, A1C, weight and cost.

How each medication works

Dulaglutide is a GLP-1 receptor agonist whose amino acid sequence is 90% the same as human GLP-1, per its label. It helps the pancreas release insulin when blood sugar is high and slows stomach emptying. Tirzepatide activates both GIP and GLP-1 receptors, and a fatty-acid chain that binds albumin stretches its half-life to about 5 days, matching dulaglutide, so both are weekly shots. The explainer on how the dual mechanism works goes deeper.

A1C results in trials

SURPASS-CVOT patients started at an average A1C of 8.4%. At 36 months it was down 1.66 points on tirzepatide and 0.88 on dulaglutide 1.5 mg (ClinicalTrials.gov, NCT04255433).

SURPASS J-mono, a smaller double-blind trial in Japan, used a low dulaglutide dose, 0.75 mg. Over 52 weeks, A1C fell 2.4 to 2.8 points on tirzepatide 5 to 15 mg, against 1.3 on dulaglutide (Lancet Diabetes Endocrinol, 2022).

Neither trial tested Trulicity at 3 or 4.5 mg. In a separate 36-week trial, Trulicity 4.5 mg lowered A1C 1.8 points against 1.5 on 1.5 mg (Trulicity prescribing information), so it says nothing direct about Mounjaro.

Weight loss results

Neither drug is FDA approved for weight loss, so Mounjaro vs Trulicity weight loss figures come from diabetes trials. At 36 months in SURPASS-CVOT, weight fell 11.6% on tirzepatide and 4.8% on dulaglutide 1.5 mg. In SURPASS J-mono it fell 10.7 kg on tirzepatide 15 mg and 0.5 kg on dulaglutide 0.75 mg.

Higher Trulicity doses add a little: 3.0, 3.8 and 4.6 kg lost on 1.5, 3 and 4.5 mg over 36 weeks. Tirzepatide also has a weight-management brand, Zepbound, approved for adults with obesity or with overweight and a related condition (Zepbound prescribing information). Dulaglutide has no such version.

Dosing & cost

Mounjaro starts at 2.5 mg once a week and, if more glucose control is needed, rises in 2.5 mg steps at least 4 weeks apart, up to 15 mg for adults (Mounjaro prescribing information). Since August 2026 the label also allows 2.5 mg as an ongoing dose (Drugs@FDA). Trulicity starts at 0.75 mg, can move to 1.5 mg after 4 weeks, then climbs in 1.5 mg steps to 4.5 mg. It comes only in single-dose pens, while Mounjaro also comes in vials and a 4-dose KwikPen.

Wholesale prices sit close on Mounjaro vs Trulicity cost. The ADA's 2026 tables put the median average wholesale price of a tirzepatide 15 mg pen at $1,296 a month and a dulaglutide 4.5 mg pen at $1,185, before discounts. A November 2025 federal pricing agreement set Trulicity at $389 a month through TrumpRx (White House, 2025). Harbor lists compounded tirzepatide at $149 a month, flat as the dose rises.

Compounded tirzepatide is not Mounjaro and is not FDA approved. Licensed U.S. pharmacies prepare it, and FDA does not review compounded drugs for safety, effectiveness or quality before they are marketed (FDA). FDA declared the tirzepatide shortage resolved on December 19, 2024, and its shortage-era leeway for compounders ended in March 2025 (FDA). Every trial result here comes from the brand drugs.

Which is better Trulicity or Mounjaro depends on your goals and history, and for type 2 diabetes your diabetes clinician makes that call.

Mounjaro may fit better when:

• A larger A1C drop matters most, as SURPASS-CVOT showed
• Losing weight is also part of your diabetes plan
• Your clinician favors acting on both GIP and GLP-1 receptors

Trulicity may fit better when:

• You already reach your A1C goal on it
• Your clinician favors the longer record, with FDA approval since 2014
• Cost decides it and the $389 TrumpRx cash price works for you

If your goal is weight loss rather than diabetes care, Harbor compounded tirzepatide is a weekly program for adults seeking medically supervised weight loss, typically with a BMI of 27 or higher. It is not FDA approved. A board-certified physician first reviews your health history, goals and prior treatment response, and if it is not the right fit, you are not charged. With type 2 diabetes, keep your diabetes clinician informed.

SURPASS-CVOT did not test a switch. Still, it is a reason to ask about switching from Trulicity to Mounjaro when A1C or weight goals are not met.

There is no Trulicity to Mounjaro conversion chart. Neither label lists one, and the Mounjaro label gives one starting dose, 2.5 mg weekly, with no separate schedule for people coming from another GLP-1 drug. Your prescriber times the last Trulicity dose and the first Mounjaro dose.

Mounjaro is approved for type 2 diabetes, not weight management. If weight is your main goal and you do not have diabetes, weigh Mounjaro pricing vs compounded tirzepatide with a licensed clinician, knowing the compounded version is not FDA approved.