What is the difference between Trulicity and Mounjaro?

If you have type 2 diabetes, you’ve likely done a lot of thinking about how to best manage your blood sugar, including whether GLP-1 medications like Trulicity and Mounjaro make sense for your specific situation. And, if so, which one? You don’t have to figure out the answer to those questions alone — and in fact, you shouldn’t! Your healthcare provider is the best person to explain these medications to you and help you see if one of them is a good fit or not. But if you want to come to that conversation armed with some base knowledge of Trulicity versus Mounjaro, keep reading for expert insight on their similarities and differences.

What is Trulicity?

Trulicity is a brand name of dulaglutide, which belongs to a class of drugs called glucagon-like peptide 1 receptor agonists (GLP-1s). This once-weekly, injectable medication is approved to treat type 2 diabetes and mimics your body’s natural GLP-1, a gut hormone that plays a role in regulating your appetite, digestion, and blood sugar.

Trulicity stabilizes your blood sugar levels in two big ways: It helps your pancreas release insulin when your blood sugar is high, and limits the amount of sugar that moves from your liver to your bloodstream. It also slows down how quickly food empties from your stomach, helping you feel fuller for longer and aiding in weight loss. Dulaglutide activates GLP-1 receptors in the brain that regulate hunger and energy balance as well, further enhancing satiety signals and reducing food intake.

What is Mounjaro?

Mounjaro is a brand name of tirzepatide, which is called a dual agonist because it mimics two hormones: GLP-1 and glucose-dependent insulinotropic polypeptide (GIP), another gut hormone that influences your appetite, digestion, and blood sugar.

Like Trulicity, Mounjaro is a once-weekly injection approved for type 2 diabetes and has similar ways of working. It helps your pancreas release insulin when blood sugar is high, prevents your liver from making and releasing too much sugar into your blood, and slows down how quickly food leaves your stomach. It can also curb your appetite, aiding in weight loss.

Do Trulicity and Mounjaro have generic versions?

No, at the moment, only brand-name versions of dulaglutide and tirzepatide are approved by the FDA.

Key differences between Trulicity and Mounjaro

The main differences between Trulicity and Mounjaro boil down to their main active ingredients, potential efficacy, and for whom each medication is considered:

• Active ingredients: Trulicity’s active ingredient is dulaglutide, which mimics one hormone: GLP-1. Mounjaro’s active ingredient, tirzepatide, mimics two hormones: GLP-1 and GIP.
  
  
• Efficacy: Mounjaro is typically more effective than Trulicity at lowering A1c (a test used to measure blood sugar over time) and promoting weight loss in people with type 2 diabetes, says Dr. Silvana Obici, M.D., professor of medicine and medical director of diabetes services at Stony Brook Medicine in New York.
  
  
• FDA approvals: Unlike Mounjaro, which is only approved to treat type 2 diabetes in adults, Trulicity is approved to treat the condition in adults and children 10 and up. Trulicity is also approved to reduce the risk of major heart-related events in adults with type 2 diabetes who have been diagnosed with cardiovascular disease or have multiple risk factors.

Trulicity vs. Mounjaro uses

Trulicity and Mounjaro are manufactured by the same parent company, Eli Lilly, and are both once-weekly, at-home injections approved by the FDA to treat type 2 diabetes. Neither is approved as a weight loss medication, even though they both may result in weight loss.

Obici says many of her patients get confused by this because Mounjaro has a direct weight-loss counterpart: Zepbound (also tirzepatide). “They are the same drug,” Obici explains. The difference: Mounjaro is only approved to treat type 2 diabetes, while Zepbound is only approved to treat people with obesity or with overweight and a secondary condition like hypertension, type 2 diabetes, or sleep apnea.

Also worth noting: Trulicity is approved by the FDA to reduce cardiovascular events in adults with type 2 diabetes who face a higher risk. The REWIND study — which followed nearly 10,000 patients with type 2 diabetes over an average of five years — found that the 1.5 mg dose of Trulicity reduced the risk of cardiovascular disease-related death and nonfatal heart attack and stroke by 12%. (Researchers are exploring whether Mounjaro could offer similar benefits, and clinical trials are promising so far.)

Trulicity vs. Mounjaro dosages and administration

Trulicity dosage options include four strengths: .75 mg, 1.5 mg, 3 mg, and 4.5 mg. In comparison, Mounjaro dosage options come in six tiers: 2.5 mg, 5 mg, 7.5 mg, 10 mg, 12.5 mg, and 15 mg.

Whether you’re on a Trulicity prescription or Mounjaro prescription, your healthcare provider will start you at the lowest dose of the medication to reduce your risk of side effects. Your doctor will then slowly increase your dosage — usually going up every four weeks — depending on your A1c improvement and what side effects you may be feeling. “You have to tailor the management to each patient,” Obici says.

“Because they’re both made by the same manufacturer, the pen and the dispensing device are essentially the same,” says Dr. Veronica Johnson, M.D., assistant professor and obesity medicine specialist at Northwestern University’s Feinberg School of Medicine. To administer the medication, you place the injectable side of the pen directly on the skin of your abdomen, thigh, or upper arm, and then press the button at the other end of the pen. “When you first press the button, you’ll hear a click. Once the medication is done being administered, you’ll hear another click,” signaling the injection is complete, Johnson explains. “I generally advise patients to hold for another five to 10 seconds on the surface of the skin to ensure they’ve gotten the whole dose of the medication.”

Effectiveness of Trulicity vs. Mounjaro

Based on the data we have, Mounjaro is widely accepted among clinicians as the “most effective” GLP-1-based medication for type 2 diabetes, Johnson says. For example, in a 2022 study that compared Mounjaro and Trulicity, patients with type 2 diabetes who took Mounjaro reduced their A1c between 2.4% and 2.8% in a year, depending on their dose. Those taking .75 mg of Trulicity (the lowest dose) had a 1.3% A1c reduction (researchers did not compare higher doses of Trulicity in the trial).

A recent head-to-head, phase 3 trial also backs the higher effectiveness of Mounjaro. The researchers followed type 2 diabetes patients with heart disease for about five years; those who took Mounjaro reduced their A1c by up to 1.73% within 36 months, while those taking 1.5 mg of Trulicity had a .9% A1c reduction in the same period.

As for the weight loss that often occurs when taking these medications, it’s also typically greater on Mounjaro — about 14.7% with Mounjaro versus 5% with Trulicity per the recent phase 3 trial — but this is highly dependent on an individual’s ability to tolerate the medication’s side effects as they ramp up their dosage, as well as the lifestyle changes they also make.

This is all likely due to the fact that Mounjaro contains both GLP-1 and GIP. The GIP component doesn’t just amplify GLP-1s effects on blood sugar and hunger — it also has its own effect on fat storage and cholesterol levels.

Trulicity vs. Mounjaro cost and insurance coverage

The cost of Trulicity (the original price set for a medication by a manufacturer before any discounts are applied) is $987.19 per month, while Mounjaro costs $1,079.77 per month. Eli Lilly also offers savings programs for each medication; you can explore options for Trulicity here and Mounjaro here.

Health insurance coverage varies based on your provider, but most plans cover type 2 diabetes medications for those diagnosed with the condition. However, that doesn’t mean Trulicity or Mounjaro will be covered right away. Your insurance company may ask that you try a less expensive medication to manage your blood sugar first, according to both Johnson and Obici. “Some insurance providers would like to see a patient ‘fail’ [the less expensive] option before possibly covering a more effective option like Mounjaro,” Johnson explains.

This is only the case if you’re receiving a prescription for their intended use of managing type 2 diabetes. If your provider prescribes either medication for weight loss, known as off-label use, you’ll likely have to pay out of pocket.

Trulicity vs. Mounjaro side effects

The most common side effects for both Trulicity and Mounjaro center around your gastrointestinal system — nausea is the most common, but acid reflux, constipation, diarrhea, and vomiting are also possible.

But you don’t have to put up with the discomfort. “If a patient’s having significant nausea and vomiting, we can give them anti-nausea medication,” Johnson explains. “Or if they’re having constipation, we can counsel them on increasing their fiber intake and hydration.” That’s why a lifestyle program like WeightWatchers, which includes consultations with registered dietitians, can be a worthwhile resource when using these medications.

Trulicity side effects

Common Trulicity side effects include:

• Nausea
• Diarrhea
• Constipation
• Vomiting
• Abdominal pain
• Decreased appetite
• Gassiness
• Heartburn
• Fast heartbeat
• Fatigue

Rarer but serious side effects include:

• Low blood sugar (when combined with other diabetes medications)
• Heart palpitations
• Severe allergic reactions
• Pancreatitis

You can see a full list of Trulicity’s potential side effects here.

Mounjaro side effects

Common Mounjaro side effects are similar to Trucility's and can include:

• Nausea
• Diarrhea
• Constipation
• Vomiting
• Abdominal pain
• Decreased appetite
• Gassiness
• Indigestion
• Fatigue

Rarer but serious side effects include:

• Low blood sugar (when combined with other diabetes medications)
• Kidney problems
• Gallbladder problems
• Prolonged stomach problems
• Severe allergic reactions
• Pancreatitis
• Vision changes

You can see all of Mounjaro’s potential side effects here.

Trulicity and Mounjaro drug warnings

While Trulicity and Mounjaro are generally considered safe, both feature a black box warning, the FDA’s most serious, due to a potential risk of thyroid C-cell tumors, including the rare medullary thyroid carcinoma (MTC). It’s crucial to note that the warning is based on rodent studies, and the same risk has not yet been identified in humans. That said, neither medication should be used in people with a personal or family history of MTC or who have multiple endocrine neoplasia syndrome type 2 (MEN 2).

The bottom line

Trulicity and Mounjaro are both FDA-approved type 2 diabetes medications, but they work in slightly different ways: Trulicity is a GLP-1 agonist, while Mounjaro is a dual GLP-1/GIP agonist. Both are effective in lowering A1c and aiding weight loss, but Mounjaro shows higher efficacy in type 2 diabetes and weight loss in clinical trials. They work similarly in the body, which is why they have similar side effects that most commonly affect your gastrointestinal system. Insurance providers are likely to cover these medications for type 2 diabetes, but plan specifics differ and your doctor may be required to prescribe a less-expensive medication first.