Wegovy (semaglutide) and Mounjaro (tirzepatide) are brand-name injections. Wegovy is prescribed for weight loss. Mounjaro is approved for type 2 diabetes, but doctors may sometimes prescribe it off-label for weight loss.
This article explains the main similarities and differences between Wegovy and Mounjaro. If you’re considering taking one of these drugs, discussing this information with your doctor can help you decide whether one of these treatments may be right for you.
Note: For more comprehensive information about these two drugs, you can refer to our Wegovy and Mounjaro articles.
Key differences between Wegovy and Mounjaro
These are a few of the main differences between Wegovy and Mounjaro:
- Conditions treated: Doctors may prescribe Wegovy or Mounjaro for weight loss, but the Food and Drug Administration (FDA) has only approved Wegovy for this use. Mounjaro is currently FDA-approved for type 2 diabetes. Doctors may prescribe it off-label* for weight management. (See the “Uses of Wegovy vs. Mounjaro” section.)
- How they work: Wegovy and Mounjaro mimic the action of a hormone that helps regulate your appetite, called glucagon-like peptide-1 (GLP-1). Mounjaro also mimics another appetite-regulating hormone called glucose-dependent insulinotropic polypeptide (GIP).
* With off-label use, a drug is prescribed for a use other than that approved by the FDA.
Here’s information about the generic status for Wegovy and Mounjaro, as well as details on their active ingredients.
Wegovy | Mounjaro | |
Generic available | no | no |
Active ingredient | semaglutide | tirzepatide |
Drug class | glucagon-like peptide-1 (GLP-1) receptor agonist | dual glucose-dependent insulinotropic polypeptide (GIP) and GLP-1 agonist |
Wegovy and Mounjaro are both prescribed for weight loss and long-term weight management. But for Mounjaro, this is an off-label use. With off-label use, a drug is prescribed for a use other than that approved by the Food and Drug Administration (FDA).
The FDA has approved Wegovy and Mounjaro for the following uses in adults:
- Wegovy is FDA-approved to:
- help with long-term weight management, along with diet and exercise, in:
- adults with a body mass index (BMI) of 30 or higher (obesity)
- adults with a BMI of 27 or higher (overweight) and at least one weight-related health condition, such as high cholesterol, high blood pressure, or diabetes
- help with long-term weight management, along with diet and exercise, in:
- Mounjaro is FDA-approved to:
- help improve blood sugar levels, along with diet and exercise, in adults with type 2 diabetes
Wegovy or Mounjaro and children
Doctors prescribe Wegovy together with diet and exercise to help long-term weight management in certain children. Wegovy is FDA-approved for children ages 12 years and older with a BMI in the 95th percentile or higher (obesity).
Mounjaro is not approved for use in children under age 18 years.
Here’s a quick look at the dosage and administration of Wegovy and Mounjaro for the conditions both drugs treat.
Dosage for weight management and type 2 diabetes
Here are the recommended doses of Wegovy and Mounjaro for weight management and type 2 diabetes in adults. Doses are given in milligrams per milliliter (mg/mL) of solution.
Wegovy for weight management | Mounjaro for type 2 diabetes (and off-label for weight management) | |
Forms | subcutaneous injection | subcutaneous injection |
Strengths | prefilled single-dose injection pens: • 0.25 mg/0.5 mL • 0.5 mg/0.5 mL • 1 mg/0.5 mL • 1.7 mg/0.75 mL • 2.4 mg/0.75 mL | prefilled single-dose injection pens: • 2.5 mg/0.5 mL • 5 mg/0.5 mL • 7.5 mg/0.5 mL • 10 mg/0.5 mL • 12.5 mg/0.5 mL • 15 mg/0.5 mL |
Dose | • weeks 1–4: 0.25 mg • weeks 5–8: 0.5 mg • weeks 9–12: 1 mg • weeks 13–16: 1.7 mg • week 17 onwards: 2.4 mg | • weeks 1–4: 2.5 mg • weeks 5–8: 5 mg • week 9 onwards:if needed, your doctor may increase your dose by 2.5 mg every 4 weeks, up to a maximum of 15 mg |
Frequency | once per week | once per week |
Given by | self (see below) | self (see below) |
Your doctor or another healthcare professional can teach you how to inject Wegovy or Mounjaro. With both drugs, the injection is administered into your upper arm, abdomen, or thigh.
Children’s dosage
Wegovy is FDA-approved for weight management in certain children ages 12 years and older. The recommended dosage is the same as for adults. This is described above.
Doctors may prescribe Wegovy or Mounjaro for weight management. (This is an off-label* use for Mounjaro.) These drugs can cause some of the same side effects, as well as some different ones. Some of the side effects reported in clinical trials of these drugs are mentioned below.
For more details about side effects of the two drugs, see our side effect articles about Wegovy and Mounjaro. You can also refer to the Wegovy prescribing information and Mounjaro prescribing information.
* With off-label use, a drug is prescribed for a use other than that approved by the Food and Drug Administration (FDA).
Mild side effects
The following table lists some of the more commonly reported mild side effects of Wegovy and Mounjaro. The table may also include mild side effects that are less common but that you might have concerns about in some cases.
Mild side effects | Wegovy | Mounjaro |
nausea and vomiting | ✓ | ✓ |
constipation | ✓ | ✓ |
diarrhea | ✓ | ✓ |
burping or gas | ✓ | ✓ |
abdominal pain or bloating | ✓ | ✓ |
indigestion | ✓ | ✓ |
injection site reactions | ✓ | ✓ |
fatigue | ✓ | |
dizziness | ✓ | |
mild allergic reaction | ✓ | ✓ |
These side effects may be temporary, lasting a few days to weeks. If the side effects last longer than that, bother you, or become severe, be sure to talk with your doctor or pharmacist.
Serious side effects
The following table lists the reported serious side effects of Wegovy and Mounjaro.
Serious side effects | Wegovy | Mounjaro |
risk of thyroid cancer* | ✓ | ✓ |
gallbladder problems, such as gallstones | ✓ | ✓ |
pancreatitis (inflammation of the pancreas) | ✓ | ✓ |
hypoglycemia (low blood sugar level) | ✓ | |
acute (sudden) kidney failure | ✓ | ✓ |
increased heart rate | ✓ | ✓ |
severe nausea, vomiting, and diarrhea | ✓ | |
severe allergic reaction | ✓ | ✓ |
If you have serious side effects while using Wegovy or Mounjaro, call your doctor immediately. If the side effects feel life threatening or you believe you’re having a medical emergency, call 911 or your local emergency number right away.
* Wegovy and Mounjaro have a boxed warningfor this side effect. A boxed warning is aserious warning from the FDA. To learn more, see the “Precautions for Wegovy and Mounjaro” section below.
You may wonder whether Wegovy or Mounjaro is more effective for helping with weight loss. Note that this is an off-label* use for Mounjaro. Mounjaro is FDA-approved to help improve blood sugar levels in people with type 2 diabetes. But in clinical trials, it was also found to cause weight loss in people with type 2 diabetes.
Review of studies. Here’s a brief look at whether Wegovy or Mounjaro was found to be more effective for helping with weight loss.
Wegovy and Mounjaro haven’t been directly compared for weight loss in clinical trials. But the weight loss effect of these drugs in people with type 2 diabetes has been compared in a review of trials. In this review, Mounjaro, taken at the maximum dose of 15 milligrams (mg) once per week, was found to cause greater weight loss than Wegovy, taken at the maximum dose of 2.4 mg once per week.
Another
Keep in mind that trials and reviews of trials may not apply to your individual health situation. Be sure to talk with your doctor to determine whether Wegovy or Mounjaro may be right for you.
Prescribing information. For details about how these drugs performed in clinical trials, see the prescribing information for Wegovy and Mounjaro. Keep in mind that trial results may not apply to your individual health situation.
Treatment guidelines. Another way to see whether a drug is considered effective is to look at treatment guidelines.
When an organization includes certain drugs in treatment guidelines, this means that research has shown the drug to be safe and effective. Wegovy is recommended as a treatment option for people with obesity in guidelines from the American Gastroenterological Association.
Mounjaro is recommended as a treatment option for people with type 2 diabetes in guidelines from the American Diabetes Association. In particular, it’s recommended for those who could benefit from medication that helps with weight management.
* With off-label use, a drug is prescribed for a use other than that approved by the Food and Drug Administration (FDA).
How much Wegovy or Mounjaro costs depends on the treatment plan your doctor prescribes, your insurance plan, and your pharmacy. You can visit Optum Perks* for price estimates of Wegovy and Mounjaro.
Both Wegovy and Mounjaro are brand-name drugs. They’re not currently available in generic form.
* Optum Perks is a sister site of Medical News Today.
Wegovy and Mounjaro may not be right for you if you have certain medical conditions or other factors that affect your health. The drugs share some of the same precautions, but they also have different ones. Some of these precautions are mentioned below.
Boxed warning: Risk of thyroid cancer
Wegovy and Mounjaro both have a boxed warning for a possible risk of thyroid cancer. A boxed warning is the most serious warning from the Food and Drug Administration (FDA). It alerts doctors and patients about drug effects that may be dangerous.
Semaglutide (the active drug in Wegovy) and tirzepatide (the active drug in Mounjaro) have both been found to cause thyroid tumors in rats and mice. It’s not known whether these drugs can cause thyroid cancer in humans.
Due to the possible risk, your doctor will likely not prescribe Wegovy or Mounjaro if you:
- have a personal or family history of a type of thyroid cancer called medullary thyroid carcinoma
- have an inherited condition that can raise your risk of thyroid cancer, called multiple endocrine neoplasia type 2
If you take Wegovy or Mounjaro, tell your doctor if you develop the symptoms below, as these could be signs of thyroid cancer:
- trouble swallowing or breathing
- lump in your neck
- hoarse voice that doesn’t get better
Precautions
In addition to boxed warnings, Wegovy and Mounjaro have other warnings.
If any of the following medical conditions or other health factors are relevant to you, talk with your doctor before using Wegovy or Mounjaro for weight loss. (Note that this is an off-label* use for Mounjaro.)
Precaution | Wegovy | Mounjaro |
if you’ve had an allergic reaction to either drug or any of its ingredients | ✓ | ✓ |
if you’ve had an allergic reaction to other glucagon-like peptide-1 (GLP-1) receptor agonist drugs | ✓ | ✓ |
if you’re pregnant or thinking about becoming pregnant | ✓ | ✓ |
if you’re breastfeeding or thinking about breastfeeding | ✓ | ✓ |
if you have a history of pancreatitis (inflammation of the pancreas) | ✓ | ✓ |
if you have type 2 diabetes | ✓ | ✓ |
if you have a history of diabetic retinopathy (eye disease caused by diabetes) | ✓ | ✓ |
if you have kidney problems | ✓ | ✓ |
if you have severe digestive problems, such as gastroparesis (slow stomach emptying) | ✓ | |
if you have depression, thoughts of suicide, or another mental health condition | ✓ |
Note: For more comprehensive information about these two drugs, you can refer to our Wegovy and Mounjaro articles.
* With off-label use, a drug is prescribed for a use other than that approved by the FDA.
Switching between Wegovy and Mounjaro might be possible.
If you’d like to know more about switching between Wegovy and Mounjaro, talk with your doctor. They can give you additional details and help determine the best course of action for your personal situation. Even if two drugs treat the same condition or are in the same drug class, your body can still respond differently.
It’s important that you do not stop, start, or switch any of your drug treatments without your doctor’s recommendation.
Some key points to remember when comparing Wegovy and Mounjaro include:
- Both Wegovy and Mounjaro may be prescribed for weight loss and long-term weight management, but currently, the Food and Drug Administration (FDA) has only approved Wegovy for this use. (Mounjaro is FDA-approved for improving blood sugar levels in type 2 diabetes.)
- Both drugs are effective for weight loss, but Mounjaro may cause more weight loss than Wegovy.
- These drugs can cause similar side effects.
If you’d like to learn more about Wegovy or Mounjaro, talk with your doctor or pharmacist. They can help answer any questions you have about similarities and differences between the drugs. They can also help determine whether one drug or the other might work well for you.
Note: For more information about weight loss and long-term weight management, see our weight management hub.
Disclaimer: Medical News Today has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.