Mounjaro vs. metformin: Key differences and which is better for you.

In this article:

• Main differences
• Conditions treated
• Efficacy
• Cost and Coverage
• Side effects
• Interactions
• Warnings
• FAQ

In this article

• Main differences
• Conditions treated
• Efficacy
• Cost and Coverage
• Side effects
• Interactions
• Warnings
• FAQ

People with Type 2 diabetes may often find themselves choosing between different treatment options for their condition. While many people may be familiar with metformin as a standard diabetes medication, they might also look at newer options like Mounjaro. Both Mounjaro and metformin may help control blood sugar levels and reduce the risk of diabetes complications like high blood pressure, cardiovascular disease, and diabetic retinopathy.

Although both medications are FDA approved to treat Type 2 diabetes, they differ in many ways. Choosing the right medication may involve weighing multiple factors, such as side effects, insurance coverage, and personal health goals. By comparing the two, you work with your doctor or healthcare provider to find the best treatment option. 

What are the main differences between Mounjaro and metformin?

Mounjaro is a brand-name medication manufactured by Eli Lilly and Company. Metformin is a generic drug manufactured by various pharmaceutical companies. The brand names of metformin include Glucophage, Riomet, and Glumetza. 

A key difference between Mounjaro and metformin lies in their active ingredients and how they work. Mounjaro contains tirzepatide, a GIP/GLP-1 receptor agonist. It lowers blood glucose levels by increasing insulin secretion and reducing the amount of sugar produced in the liver. Metformin belongs to the biguanides medication class. It helps reduce the amount of sugar made by the liver and improves insulin sensitivity.

Mounjaro is available as a subcutaneous injection or injection under the skin, which is taken once a week. It may be more convenient for people who prefer less frequent dosing. Metformin is taken as an oral tablet, sometimes multiple times a day. The choice between a weekly injection or a daily pill may influence a person’s treatment plan and lifestyle.

Conditions treated by Mounjaro and metformin

Mounjaro and metformin are both approved to control high blood sugar levels in people with Type 2 diabetes. Mounjaro can treat Type 2 diabetes in adults 18 and older, while metformin can treat Type 2 diabetes in adults and children 10 and older. By managing insulin resistance, these diabetes medications may help reduce the risk of complications from diabetes. 

In addition to their approved uses, both Mounjaro and metformin may sometimes be prescribed off-label. Mounjaro may be prescribed to manage weight in people with obesity. However, it’s not approved for this use. The active ingredient of Mounjaro is available under a different brand name, Zepbound, which is approved for the treatment of obesity in adults.

Metformin may be prescribed off-label for gestational diabetes and polycystic ovary syndrome to manage insulin sensitivity. It may also be used to control weight gain as a side effect of antipsychotic medications like Zyprexa (olanzapine), Clozaril (clozapine), and Risperdal (risperidone). Metformin is the only ADA-recommended medication for prediabetes, helping to prevent progression to Type 2 diabetes.

Neither medication is approved for use in people with Type 1 diabetes. 

Is Mounjaro or metformin more effective?

Clinical studies have shown that Mounjaro and metformin are both effective for treating Type 2 diabetes. Metformin is often the first-line option for treating Type 2 diabetes. However, Mounjaro may be prescribed for improved glucose control, especially in people who may be overweight or obese. 

Research shows that Mounjaro tends to lead to more significant reductions in A1C levels than metformin. A1C is a blood test that gives an average of your blood sugar levels over the past few months. With Mounjaro, people can expect their A1C levels to drop by around 2%. In contrast, metformin lowers A1C levels by an average of around 1% to 1.5%.

In many cases, Mounjaro and metformin may be used together. According to the American Association of Clinical Endocrinology/American College of Endocrinology (AACE/ACE) guidelines, Mounjaro is recommended as a preferred drug to add to metformin for people who are not meeting their blood sugar goals with metformin alone. This combination may be particularly helpful for people who are overweight, those who might be at risk for low blood sugar, or anyone who has had serious high blood sugar problems.

Always consult a healthcare provider to determine the most appropriate treatment option. The best option may vary based on a person’s medical history and overall condition.

Coverage and cost comparison of Mounjaro vs. metformin

Metformin is a generic drug that is usually covered by many insurance plans and Medicare. Since it is often the first medication prescribed for managing diabetes, most insurance companies offer coverage options to help people access it. However, the price of metformin can vary based on the pharmacy and the specifics of your insurance coverage.

Mounjaro, on the other hand, is a brand-name drug that not all insurance plans may cover fully. Therefore, it may have higher out-of-pocket costs. The actual cost of Mounjaro can vary based on the insurance plan and the pharmacy you get it from.

Retail costs for both medications can differ based on the quantity prescribed and the pharmacy where the prescription is filled. However, for those without insurance, Mounjaro is generally more expensive than metformin as a brand-name drug. If you’re looking to save money on prescription drugs, you can explore discount programs. For instance, you could use SingleCare coupons to potentially lower the cost of these medications.

Common side effects of Mounjaro vs. metformin

Mounjaro and metformin share similar side effects. One of the most common side effects of both medications is stomach-related side effects, such as nausea, vomiting, diarrhea, constipation, indigestion, and abdominal pain. However, not everyone experiences these issues.

In addition to stomach-related side effects, Mounjaro may cause decreased appetite. On the other hand, metformin may be more likely to cause headache and weakness than Mounjaro. 

Serious side effects, such as low blood sugar (hypoglycemia) and allergic reactions, are also possible. Always consult a healthcare provider or drug-label information for a comprehensive list of potential side effects.

Frequency is not based on data from a head-to-head trial. This may not be a complete list of adverse effects that can occur. Please refer to your doctor or healthcare provider to learn more.

Source: DailyMed (Mounjaro), DailyMed (metformin)

Drug interactions of Mounjaro vs. metformin

Mounjaro and metformin interact with similar types of medications, which can affect how the drugs work or lead to side effects. For example, both drugs can interact with insulin and other diabetes medications like sulfonylureas and glinides. When used together, they might increase the risk of low blood sugar levels. 

Mounjaro can slow down how quickly substances leave the stomach, which may affect the absorption of other medications. This means that if you take other oral medications at the same time as Mounjaro, they might not work as well because they are not absorbed into your body properly. 

Metformin can interact with carbonic anhydrase inhibitors. When these two types of drugs are taken together, there may be a higher risk of lactic acidosis, a serious condition in which too much lactic acid builds up in the body.

Some medications, like corticosteroids, can affect blood sugar control when taken with Mounjaro or metformin. This interaction might lead to higher blood sugar levels, complicating diabetes management.

Consult a healthcare professional for other possible drug interactions

Warnings of Mounjaro and metformin

Both Mounjaro and Metformin can increase the risk of low blood sugar (hypoglycemia), especially when used with other diabetes medications like insulin. It’s important to watch for signs of low blood sugar, such as dizziness, sweating, or confusion, and adjust other medications if necessary. 

Mounjaro has been linked to a potential risk of thyroid tumors, though this has only been seen in animal studies. People with a personal or family history of medullary thyroid carcinoma or multiple endocrine neoplasia syndrome type 2 (MEN 2) should avoid Mounjaro. This medication may also trigger pancreatitis and gallbladder issues like gallstones. 

Metformin carries a risk of lactic acidosis, a serious condition in which lactic acid builds up in the body. This is more likely in those with liver or kidney problems and heavy alcohol use. Symptoms of lactic acidosis may include weakness, difficulty breathing, or severe stomach pain. Metformin may also lead to vitamin B12 deficiency, so regular check-ups are recommended, especially if you experience fatigue or weakness.

Consult a healthcare provider for medical advice before using either medication. To avoid complications, tell your healthcare provider about your overall medical history and medical conditions.

Frequently asked questions about Mounjaro vs. metformin

What is Mounjaro?

Mounjaro is an FDA-approved medication for managing Type 2 diabetes. It is given as a once-weekly injection and works by helping to lower blood sugar levels. When combined with lifestyle changes like a healthy diet and physical activity, this medication may also contribute to weight loss.

What is metformin?

Metformin is an oral medication commonly prescribed for the treatment of Type 2 diabetes. It helps lower blood sugar levels and is often one of the first medications recommended for diabetes management. Metformin is a daily medication that may be used alongside other diabetes treatments.

Are Mounjaro and metformin the same?

No, Mounjaro and metformin are not the same. Mounjaro is a once-weekly injection, whereas metformin is an oral medication taken daily. They belong to different classes of medications and work in different ways to help manage diabetes mellitus.

Is Mounjaro or metformin better?

Whether Mounjaro or metformin is better depends on individual health needs and medical advice. Clinical trials have shown that both medications are effective in lowering blood sugar levels. Your healthcare provider can help determine which medication is more appropriate for you. In some cases, Mounjaro and metformin may be used together. 

Can I use Mounjaro or metformin while pregnant?

Metformin may be prescribed off-label for gestational diabetes. However, pregnant women should talk to their doctor before using Mounjaro or metformin. The safety of these medications during pregnancy can vary, so getting professional medical advice is important to protect the health of both the mother and the baby.

Can I use Mounjaro or metformin with alcohol?

It is generally recommended to limit alcohol consumption while taking Mounjaro or metformin. Alcohol can affect blood sugar levels and may increase the risk of gastrointestinal side effects. Always seek professional medical advice regarding alcohol use with these medications.