In the world of prescription weight loss drugs, Wegovy (semaglutide) has been in the spotlight since its FDA approval for chronic weight management in June of 2021. But recently, another drug, Mounjaro (tirzepatide), has also been taking center stage. If you’re looking to kickstart your weight loss journey, you may be wondering about the similarities and differences between these two popular medications and, ultimately, which one offers the most effective outcomes.
While your doctor can best advise you on which (if any) prescription drug will be the best fit based on your weight loss goals and medical history, educating yourself about the various options is always recommended. To this end, we’ve put together a direct comparison of Wegovy and Mounjaro to help you gain a comprehensive understanding of each drug and how they contrast with one another.
Please bear in mind that the information below is not intended to constitute or replace medical advice.
Key Differences
- Manufacturer: Wegovy is manufactured by Novo Nordisk; Eli Lilly manufactures Mounjaro.
- Active Ingredient: Wegovy’s active ingredient is semaglutide; Mounjaro’s active ingredient is tirzepatide.
- Mechanism of Action: Semaglutide is classed as a GLP-1 receptor agonist drug, while tirzepatide is classed as a dual-targeted GLP-1 receptor agonist and GIP mimetic.
- Indications: Wegovy is indicated for chronic weight management and Mounjaro for the treatment of Type 2 Diabetes. However, both semaglutide and tirzepatide are indicated for blood glucose control and weight loss under different brand names (see more about Ozempic and Zepbound below).
- Doses: Wegovy’s maximum dose is 2.4 mg, while Mounjaro’s maximum dose is 15 mg.
What Is Wegovy?
Wegovy is a brand-name drug with the active ingredient semaglutide. Manufactured by Novo Nordisk, it’s indicated for chronic weight management in obese and overweight adults as well as in obese teens over the age of 12. Wegovy is a once-weekly medication that is injected subcutaneously into the thigh, abdomen, or upper arm.
Semaglutide belongs to the class of drugs known as GLP-1 receptor agonists. It mimics a naturally produced incretin hormone called glucagon-like peptide 1 (GLP-1), binds to its receptors, and activates its pathways throughout the body in response to food being ingested. Wegovy works in the following ways:
- It stimulates insulin secretion in the pancreas and inhibits the release of sugar from the liver, both of which help to control blood sugar levels.
- It slows down gastric emptying and the rate of digestion, allowing you to feel fuller for longer.
- It activates areas of the brain associated with appetite control, reducing cravings and hunger levels overall.
Wegovy and Ozempic
Ozempic is another brand-name semaglutide drug manufactured by Novo Nordisk. Available at lower doses than Wegovy, it’s indicated for blood sugar regulation in adults with Type 2 Diabetes but is sometimes also prescribed off-label for weight loss.
Interestingly, Ozempic came to market before Wegovy. Wegovy was subsequently FDA-approved after Ozempic’s weight loss side effects were further researched in non-diabetic populations.
What Is Mounjaro?
Mounjaro is a brand-name drug with the active ingredient tirzepatide. It is manufactured by Eli Lilly and indicated for blood sugar management in adults with Type 2 Diabetes, though sometimes also prescribed off-label for weight loss. Like Wegovy, Mounjaro is a once-weekly injectable medication.
Tirzepatide is a GLP-1 receptor agonist drug, but it also mimics a second incretin hormone known as glucose-dependent insulinotropic polypeptide (GIP). The first (and currently only) dual-targeted agonist receptor drug on the market, it effectively regulates both blood sugar levels and appetite.
See also: Mounjaro: What It Is and How Does It Work?
Mounjaro and Zepbound
Tirzepatide was recently approved for chronic weight management under the brand name Zepbound, a drug that will soon also be available from Eli Lilly. Though Mounjaro and Zepbound are indicated for different purposes, their composition is identical.
As with semaglutide, tirzepatide was first approved for treating Type 2 Diabetes and, after further research, for chronic weight management in non-diabetic populations.
Who Are Wegovy and Mounjaro Prescribed For?
As you can see, there is quite a bit of overlap between Wegovy and Mounjaro (as well as between them and their sister drugs, Ozempic and Zepbound). Let’s take a closer look at the official indications for each drug:
- In combination with diet and exercise, Wegovy is indicated for:
- Adults with obesity (BMI greater than 30), with or without other weight-related health conditions
- Overweight adults (BMI greater than 27) with at least one weight-related health condition (high blood pressure, high cholesterol, obstructive sleep apnea, etc.)
- Teens over the age of 12 with a BMI equal to or above the 95th percentile for their age and gender
- In combination with diet and exercise, Ozempic is indicated for:
- Blood sugar management and regulation in adults with Type 2 Diabetes
- Lowering the risk of major adverse cardiovascular outcomes in adults with Type 2 Diabetes and established heart disease
- In combination with diet and exercise, Mounjaro is indicated for:
- Blood sugar management and regulation in adults with Type 2 Diabetes
- In combination with diet and exercise, Zepbound is indicated for:
- Chronic weight management in obese adults (BMI greater than 30), with or without other weight-related health conditions
- Chronic weight management in overweight adults (BMI greater than 27) with a minimum of one weight-related health condition
How Wegovy and Mounjaro Are Used
Wegovy and Mounjaro are primarily used for their respective approved purposes of blood sugar control and long-term weight loss and management. That being said, they may be prescribed off-label (for a purpose other than their indicated one) if a doctor believes they will benefit the health of a particular patient.
Many GLP-1 receptor agonist drugs are prescribed off-label for weight loss purposes. Under certain circumstances, they may also be prescribed off-label for the treatment of other conditions, such as polycystic ovary syndrome (PCOS) or prediabetes.
If you are wondering about the possibility of receiving an off-label prescription for Wegovy or Mounjaro, speak with your doctor or healthcare provider.
Are There Generic Versions of Wegovy and Mounjaro?
Currently, there is no generic version of either Wegovy or Mounjaro, and both drugs will remain fully patented for many more years. In this vein, be highly cautious of any pharmaceutical services that claim to be offering low-priced generic semaglutide or tirzepatide medications. Such products are unregulated and may be detrimental to your health.
Are Wegovy and Mounjaro FDA-Approved?
Yes, both Wegovy and Mounjaro are approved by the United States Food and Drug Administration (FDA). This means that they have been deemed safe and effective for their intended uses and that any potential risks are outweighed by their overall benefit to patients.
Wegovy Vs Mounjaro: Dosage and Administration
Wegovy and Mounjaro are administered very similarly. If your doctor prescribes either of these drugs to you, they will show you exactly how to administer weekly injections properly. You can also always refer to the package insert that comes with each medication.
Generally speaking, Wegovy and Mounjaro both come in pre-filled, single-patient-use pens and must be taken on the same day each week at any time of day, with or without food. Both medications are injected under the skin of the thigh, abdomen, or upper arm (the injection site should be rotated each week) and must be taken according to the dosing schedule laid out by your doctor.
Patients begin both Mounjaro and Wegovy at a low starting dose that is titrated at 4-week intervals until an effective maintenance dosage is reached. This allows the body to adjust to increasingly higher amounts of the medication over a period of time.
Wegovy’s doses are as follows:
- Month 1: 0.25 mg (starting dose)
- Month 2: 0.5 mg
- Month 3: 1 mg
- Month 4: 1.7 mg
- Month 5 and beyond: 2.4 mg (maintenance dose)
It is standard for patients on Wegovy to maintain a 2.4 mg dosage of the drug weekly over the long term.
Mounjaro’s doses are as follows:
- Month 1: 2.5 mg (starting dose)
- Month 2: 5 mg (possible maintenance dose)
- Month 3: 7.5 mg
- Month 4: 10 mg (possible maintenance dose)
- Month 5: 12.5 mg
- Month 6 and beyond: 15 mg (highest possible maintenance dose)
Your doctor will determine which maintenance dose of Mounjaro will be most effective for your particular needs and circumstances. For weight loss, higher maintenance doses of tirzepatide (10 mg and 15 mg) are often prescribed.
Dosage for Children
Mounjaro is not approved for use in children under 18 years of age, but Wegovy is, under certain circumstances (see above). When Wegovy is prescribed to adolescents, it’s typically in the same doses and according to the same dosing schedule as for adults. That being said, each situation is unique, and it’s always critical to follow the exact instructions provided by your child’s doctor, even if they vary from standard protocol.
Wegovy and Mounjaro Side Effects
Like all prescription drugs, Wegovy and Mounjaro both come with a list of potential side effects. Some side effects are common when starting GLP-1 drugs or increasing their dose, but often clear up over time. Rarely, more serious side effects may also occur.
Always speak to your doctor if you have questions or concerns about the side effects you are experiencing. If side effects are severe, seek immediate emergency medical attention.
Wegovy Side Effects
Common and mild Wegovy side effects can include:
- Gastrointestinal issues such as nausea, vomiting, diarrhea, constipation, heartburn, and abdominal pain
- Injection site reactions
- Headache, dizziness, fatigue
More serious Wegovy side effects can include:
- Severe digestive problems
- Acute pancreas, gallbladder, or kidney problems
- Serious allergic reactions
- Severe hypoglycemia (in combination with anti-diabetic medications)
- Vision changes in people with Type 2 Diabetes (diabetic retinopathy)
- The development of thyroid tumors
For full details see Wegovy’s prescribing information.
Mounjaro Side Effects
Common and mild Mounjaro side effects can include:
- Gastrointestinal issues such as nausea, vomiting, diarrhea, constipation, acid reflux, indigestion, abdominal swelling, and loss of appetite
- Injection site reactions
More serious Mounjaro side effects can include:
- Severe gastrointestinal disease
- Acute pancreas, gallbladder, or kidney problems
- Serious allergic reactions
- Severe hypoglycemia (in combination with anti-diabetic medications)
- Vision changes in people with Type 2 Diabetes (diabetic retinopathy)
- The development of thyroid tumors
For full details see Mounjaro’s prescribing information.
Wegovy Vs. Mounjaro: Overall Effectiveness
To date, no double-blinded, randomized trial has yet directly compared Wegovy to Mounjaro. That being said, a review of existing studies and clinical trials indicates that both drugs are highly effective, but Mounjaro may be even more so under certain circumstances. Let’s take a closer look:
Wegovy Vs. Mounjaro for Diabetes
Wegovy isn’t indicated for the treatment of Type 2 Diabetes, but semaglutide is, under the brand name Ozempic. In a 2021 study comparing the effectiveness of tirzepatide and semaglutide in 1,879 patients with Type 2 Diabetes over a 40-week time period, tirzepatide was found to be equal or superior to semaglutide in terms of blood sugar control but caused slightly more adverse reactions.
Wegovy Vs. Mounjaro for Weight Loss
Mounjaro isn’t indicated for weight loss, but tirzepatide is, under the brand name Zepbound. In terms of weight management, a 2022 study indicates that tirzepatide taken at the 10 mg or 15 mg dosage can result in a bodyweight reduction of 20% or more over a 72-week time period. In comparison, 50.5% of obese and overweight adults taking once-weekly 2.4 mg semaglutide injections for 68 weeks reduced their body weight by 15% or more.
To learn more about Mounjaro (tirzepatide) for weight loss, read our blog on the topic!
Wegovy and Mounjaro: Warnings and Precautions
Wegovy and Mounjaro are generally safe drugs, but there are certain circumstances under which they should not be taken. As with their side effects, the two drugs’ warnings and precautions are similar.
You should not use Wegovy or Mounjaro if you:
- Have Type 1 Diabetes
- Are under the age of 12 (Wegovy) or 18 (Mounjaro)
- Have a known allergy to any of the medication’s ingredients
- Are taking another GLP-1 agonist drug
- Have a personal or family history of medullary thyroid carcinoma or Multiple Endocrine Neoplasia Syndrome Type 2 (MEN 2)
You should speak with your doctor before using Wegovy or Mounjaro if you:
- Are pregnant, breastfeeding, or planning to become pregnant in the near future
- Are taking anti-diabetic medications, including insulin
- Are taking oral medications, including birth control
- Have a history of pancreas, gallbladder, kidney, or severe gastrointestinal issues
Can I Switch From Wegovy to Mounjaro (or Vice Versa)?
You may be able to switch from Wegovy to Mounjaro or Mounjaro to Wegovy, but this decision must be discussed with your doctor and an appropriate transition plan made accordingly. Stopping or starting a medication without consulting your doctor can be dangerous and have serious health consequences.
Though Wegovy and Mounjaro are similar drugs, you may find that your body reacts better to one than the other. If you are experiencing ongoing side effects that are impacting your quality of life, it’s always worth exploring alternative medications with your doctor or healthcare provider.
The Verdict
To conclude, Mounjaro and Wegovy are both groundbreaking drugs that can offer unprecedented results for Americans looking to lose weight and effectively manage their blood sugar levels. Research indicates that Mounjaro (and Zepbound) may have even greater weight loss potential than Wegovy (or Ozempic), but both medications can be highly impactful when combined with healthy lifestyle interventions such as diet and exercise.
At Bisonpharmacy.com, we specialize in shipping high-quality Canadian medications to Americans at a fraction of the price they’d pay at their local pharmacy. Ready to order Ozempic or order Mounjaro online? Contact our dedicated team to learn more today!
About the Author
Ida Edlweiss Gumpal is a licensed Pharmacist and medical writer. She took her internships at Mercury Drug Corporation, Inc., a Hospital internship at De Vera Medical Center, Inc., and a Manufacturing internship at Philmed Laboratories, Inc. She has plans on attending medical school with the goal of specializing in Neurosurgery or Cardiothoracic surgery.