In the landscape of weight management solutions, two medications have emerged as significant players: Mounjaro and Wegovy. Both have gained attention for their effectiveness in aiding weight loss alongside diet and exercise.
Mounjaro, known scientifically as Tirzepatide, was initially approved by the FDA in May 2022 primarily for improving blood sugar levels in adults with type 2 diabetes. Its ability to regulate blood sugar is attributed to its unique mechanism of activating both the GLP-1 and GIP receptors, which not only aids in insulin release but also slows down food absorption, inadvertently leading to weight loss in higher doses. On the other hand, Wegovy, with its active ingredient semaglutide, was specifically approved for weight management in adults with obesity or those overweight with weight-related health conditions.
Despite Mounjaro's primary indication for diabetes, its off-label use for weight management has been noted, especially given recent authorization by the MHRA in the UK for weight loss and management in adults, signifying its expanding role beyond just diabetes care. Wegovy, meanwhile, was designed with the explicit intention of combating obesity, marking a direct approach to weight management. Both drugs work by mimicking incretin hormones that regulate appetite and insulin production but Mounjaro's dual-receptor action presents a novel approach to managing appetite and blood sugar levels.
With obesity and diabetes being major health concerns in the UK, understanding the nuances of these medications could be crucial for patients and healthcare providers alike in making informed treatment decisions. Whether you're leaning towards Mounjaro's dual-action benefits for diabetes and potential weight loss or Wegovy's targeted approach for weight management, this comparison aims to provide a comprehensive understanding to guide your health journey.
Mounjaro vs. Wegovy Comparison in Brief
| Wegovy | Mounjaro | |
| Company Name | Novo Nordisk | Eli Lilly |
| Active Ingredient | Semaglutide | Tirzepatide |
| Mechanism of Action | Mimics the action of GLP-1, a hormone that helps regulate appetite. | Mimics the action of GLP-1 and GIP, hormones that help regulate appetite and blood sugar levels. |
| Conditions Treated | Approved by MHRA for weight loss in adults with obesity or overweight individuals with weight-related health conditions. | Approved by MHRA for weight loss in adults with obesity or overweight individuals with weight-related health conditions. |
| Who Can Take It | Body Mass Index (BMI) of 30 or more; BMI between 27-30 and have weight-related health problems. | Body Mass Index (BMI) of 30 or more; BMI between 27-30 and have weight-related health problems. |
| Availability | Available on NHS and privately | Available on NHS and privately |
Technical Comparison: How They Work and The Role of GLP-1 and GIP
Wegovy: Leveraging GLP-1
Wegovy, created by Novo Nordisk, utilises semaglutide, which specifically targets the glucagon-like peptide-1 (GLP-1) receptor. GLP-1 is an incretin hormone secreted by the intestinal L cells in response to food intake. Its pivotal roles include stimulating glucose-dependent insulin secretion, thus aiding in the reduction of elevated blood glucose levels.
Additionally, GLP-1 slows gastric emptying, suppressing glucagon secretion and reducing appetite, which contributes to weight loss. By mimicking GLP-1, Wegovy effectively targets these pathways, making it particularly beneficial for weight management in adults with obesity or those overweight with related health conditions.
Mounjaro: Dual Action on GLP-1 and GIP
Mounjaro, by Eli Lilly, differentiates itself with tirzepatide, a dual agonist targeting both the GLP-1 and glucose-dependent insulinotropic polypeptide (GIP) receptors. GIP, secreted by K cells in the upper intestine, also promotes insulin secretion in a glucose-dependent manner but is traditionally considered less potent than GLP-1 in this role under pathophysiological conditions like type 2 diabetes. However, its involvement in lipid metabolism and potential effects on bone health add to the metabolic regulation. Mounjaro's dual mechanism enhances blood sugar control and weight management capabilities by not only engaging GLP-1's appetite regulation and glucose control effects but also leveraging GIP's metabolic benefits.
Who can have Mounjaro and Wegovy?
Who can use Mounjaro?
Mounjaro is indicated for managing type 2 diabetes in the following scenarios:
- As a standalone treatment for individuals who are unable to use metformin.
- In conjunction with other diabetes medications when these alone do not adequately regulate blood sugar levels. This may include oral medications and/or insulin injections.
Adherence to dietary and exercise recommendations from healthcare providers is crucial.
Mounjaro in weight management
Mounjaro is also approved for use in conjunction with a low-calorie diet and increased physical activity for weight loss and weight management in adults with:
- A BMI of 30 kg/m² or more, reflecting obesity, or
- A BMI of at least 27 kg/m² but less than 30 kg/m², indicating overweight status, with associated weight-related health concerns such as prediabetes, type 2 diabetes, high blood pressure, abnormal blood fat levels, obstructive sleep apnoea, or a history of cardiovascular events.
BMI serves as an index to measure body weight against height.
Read more about Mounjaro’s evidence-based recommendations on NICE (National Institute of Health and Care Excellence) website.
Who can use Wegovy?
Wegovy is prescribed for adults to aid in weight reduction and to help maintain weight, alongside a diet and exercise regimen. It is suitable for adults who:
- Have a Body Mass Index (BMI) of 30 kg/m² or above, indicating obesity, or
- Have a BMI between 27 kg/m² and less than 30 kg/m², signifying overweight status, coupled with weight-related health issues.
Lower BMI thresholds (usually reduced by 2.5 kg/m2) are used for people from South Asian, Chinese, other Asian, Middle Eastern, Black African or African-Caribbean family backgrounds.
It is recommended to stop Semaglutide if less than 5% of the initial weight has been lost after 6 months of treatment.
Read more about Wegovy’s evidence-based recommendations on NICE website.
How to get Mounjaro or Wegovy?
Accessing GLP-1 medications such as Wegovy or Mounjaro requires more than just a simple pharmacy visit. These treatments necessitate enrollment in a specialised weight management support programme, including a thorough assessment, prescription, and ongoing support. Wegovy and Mounjaro are not available over the counter; they can only be obtained through a structured medical process adhering to the Medicines and Healthcare products Regulatory Agency (MHRA) guidelines. Whether obtained through the NHS or privately, obtaining these medications involves a comprehensive approach to ensure they are suitable and beneficial for the individual's health and weight management goals.
To access Wegovy or Mounjaro through eMed's Weight Management Program, individuals need to complete a clinical questionnaire to determine eligibility. If eligible, the program includes GLP-1 medication, monthly clinical reviews, weekly check-ins, and progress monitoring for £189/month. Medications are delivered to the door, with ongoing support from healthcare technicians and clinicians for adjustments and side effects management. Start the journey by visiting their website for more details: eMed's Weight Management Programme.
Can I be prescribed Mounjaro by the NHS?
Yes, Mounjaro can be prescribed through the NHS for individuals with type 2 diabetes or obesity, provided they fulfil certain eligibility requirements mentioned above. The National Institute for Health and Care Excellence (NICE) declared in September 2023, its approval of Mounjaro for the treatment of those with inadequately managed type 2 diabetes. Furthermore, the Medicines and Healthcare products Regulatory Agency (MHRA) has authorised the use of Mounjaro for individuals with obesity, in conjunction with a diet and exercise regimen.
Starting from February 2024, eMed Healthcare will offer Mounjaro to those with obesity who meet our eligibility criteria.
Which Is More Effective for Weight Loss: Mounjaro or Wegovy?
When comparing the effectiveness of Wegovy and Mounjaro in terms of weight loss, data from randomised controlled trials indicate that Mounjaro results in a higher average weight loss. Specifically, studies have shown that individuals using Mounjaro can expect an average weight loss of nearly 25% after one year. This means a person weighing 100kg could potentially see a reduction of 25kg.
On the other hand, Wegovy has been associated with an average weight loss of about 16% over the same period, which is 9% less than what has been observed with Mounjaro. Furthermore, the proportion of participants achieving more than 10% weight loss—a threshold often linked to significant health benefits like reduced risks of type 2 diabetes and heart disease—is significantly higher with Mounjaro.
Read more: Switching from Semaglutide to Tirzepatide
Do you lose more weight on Mounjaro than Wegovy?
A detailed study involving 670 participants revealed that 92% of those treated with Mounjaro accomplished more than 10% weight loss, with 84% surpassing 15% weight loss. Comparatively, research involving 1,961 individuals taking Wegovy showed that 69% achieved over 10% weight loss, with 50% exceeding 15%.
In summary, evidence suggests that Mounjaro not only facilitates greater average weight loss compared to Wegovy but also supports a larger number of individuals in achieving meaningful weight loss milestones associated with substantial health improvements.
Dosages and administration comparison
Choosing the right medication is a crucial step in weight loss management. Wegovy and Mounjaro are two leading medications that offer hope for individuals looking to manage their weight effectively. The table below provides a concise overview of their dosage and administration for adults, shedding light on their differences and how they're used in the fight against obesity and type 2 diabetes.
| Wegovy for Weight Management | Mounjaro for Weight Management | |
| Form | 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 (training provided by a healthcare professional) | Self (training provided by a healthcare professional) |
| Injection Sites | Upper arm, abdomen, or thigh | Upper arm, abdomen, or thigh |
Cost of Mounjaro vs. Wegovy
Both Mounjaro and Wegoy medications are generally accessible through healthcare providers in the UK and specialised programmes, catering to a growing demand for advanced weight management options.
At eMed Healthcare, an online private GP service, has tailored a weight management programme that facilitates access to these treatments. Recognizing the importance of affordability and comprehensive support, eMed Healthcare offers these medications from £114, a reduction from the original price of £189. Although there is widespread shortage of GLP-1 medications in the UK, eMed Healthcare remains committed to supporting participants in their weight management journey.
eMed Healthcare's weight management programme offers a holistic approach by including free mental healthcare and unlimited physiotherapy, along with convenient monthly medication deliveries directly to your door. The programme is supported by weekly check-ins with a healthcare technician and monthly clinical consultations, ensuring personalised guidance and optimal management of each patient's weight loss journey.
Can I access Mounjaro or Wegovy online?
You can buy Mounjaro and Wegovy online in the UK through certain medical services, such as the eMed Weight Management programme or other registered doctor services. These are prescription treatments for weight loss, and their availability requires meeting specific eligibility criteria. It's essential to consult with a healthcare professional and follow the appropriate medical guidance to ensure these medications are suitable for you.
What you need to know before you use Mounjaro or Wegovy?
Mounjaro Warnings:
- Allergy Warning: Do not use it if allergic to Tirzepatide or any of the medicine's ingredients.
- Precautions and Warnings:
- Speak to a healthcare provider before using Mounjaro if you have severe gastroparesis, pancreatitis history, or eye problems like diabetic retinopathy or macular edema.
- Like Wegovy, there's also a risk of hypoglycemia when used with Sulfonylurea or insulin, requiring possible dose adjustments.
- Starting treatment can lead to dehydration due to nausea, vomiting, or diarrhoea, potentially affecting kidney function.
- Not studied in children under 18 years of age.
- Not recommended during pregnancy; breastfeeding women should consult a healthcare provider before use.
- Mounjaro's effect on driving and machine operation is minimal but be cautious if experiencing hypoglycemia.
Wegovy Warnings:
- Allergy Warning: Do not use if allergic to semaglutide or any other ingredients listed in the medication guide.
- Precautions and Warnings:
- Consult a healthcare provider before using Wegovy if you have kidney problems, as dehydration may occur due to nausea, vomiting, or diarrhoea.
- Wegovy should not be used as a substitute for insulin.
- There is a risk of acute pancreatitis; if severe and ongoing stomach pain occurs, seek medical attention immediately.
- There's a potential risk of low blood sugar (hypoglycemia) when used with sulfonylurea or insulin.
- Fast improvements in blood sugar control may temporarily worsen diabetic eye disease (retinopathy).
Key Safety Warnings Shared by Mounjaro and Wegovy
Both medications advise caution with use in patients who have a history of pancreatitis, are at risk of dehydration due to gastrointestinal side effects, and may cause hypoglycemia when used with other diabetes medications. They also share concerns regarding use during pregnancy and breastfeeding, with recommendations to discuss potential risks with a healthcare provider.
Understanding the Unique Safety Precautions: Mounjaro vs. Wegovy
The key differences lie in the active ingredients and specific precautions regarding their use. Wegovy's emphasis is on avoiding substitution for insulin and monitoring for signs of pancreatitis and retinopathy, whereas Mounjaro includes warnings about severe gastroparesis and the requirement for additional contraceptive measures during treatment.
Who Cannot take Mounjaro and Wegovy?
People should not use Mounjaro if they are allergic to Tirzepatide or any of its ingredients. It's advised to consult a healthcare professional before using Mounjaro if you have severe digestive problems, a history of pancreatitis, diabetic retinopathy, or are using medications for diabetes, as it may require dose adjustments to reduce the risk of low blood sugar. Pregnant or breastfeeding women, and children under 18, should avoid using Mounjaro. For Wegovy, the precautions and contraindications would be specified in its patient information leaflet, which should be consulted directly for specific details.
For detailed information on Mounjaro, please refer to www.medicines.org.uk.
Side effects comparison between Mounjaro and Wegovy
Common Mild Side Effects
The table below outlines common mild side effects reported for Wegovy and Mounjaro, including those that are less frequent but may still raise concerns.
| Mild Side Effects | Wegovy | Mounjaro |
| Nausea and vomiting | ✓ | ✓ |
| Constipation | ✓ | ✓ |
| Diarrhoea | ✓ | ✓ |
| Burping or gas | ✓ | ✓ |
| Abdominal pain or bloating | ✓ | ✓ |
| Indigestion | ✓ | ✓ |
| Injection site reactions | ✓ | ✓ |
| Fatigue | ✓ | |
| Dizziness | ✓ | |
| Mild allergic reactions | ✓ | ✓ |
These side effects are usually temporary, lasting from a few days to a few weeks. If they persist, become bothersome, or severe, contact your healthcare provider.
Serious Side Effects
Below is a list of serious side effects associated with Wegovy and Mounjaro.
| Serious Side Effects | Wegovy | Mounjaro |
| Risk of thyroid cancer* | ✓ | ✓ |
| Gallbladder issues (e.g., stones) | ✓ | ✓ |
| Pancreatitis | ✓ | ✓ |
| Hypoglycemia | ✓ | |
| Acute kidney failure | ✓ | ✓ |
| Increased heart rate | ✓ | ✓ |
| Severe nausea, vomiting, diarrhoea | ✓ | |
| Severe allergic reaction | ✓ | ✓ |
Should you experience any serious side effects while taking Wegovy or Mounjaro, immediately contact your doctor. For symptoms that appear life-threatening or for any medical emergency, call 999 or go to A&E without delay.
Is It Possible to Switch Between Mounjaro and Wegovy?
In brief: Yes, switching is feasible with your doctor's guidance.
Mounjaro and Wegovy are both similar classes of drugs utilised in conjunction with a healthy diet and exercise regimen to aid in weight loss and management. Switching between these medications might be an option for certain individuals, based on your doctor's advice.
Caution: Always consult your doctor before making any changes to your medication regimen, including stopping or switching medications.
Conclusion
GLP-1 medications like Mounjaro and Wegovy have brought a significant shift in managing obesity and type 2 diabetes. If you're considering GLP-1 medications and have a Body Mass Index (BMI) over 30, our team at eMed Healthcare is here to guide you. We offer a GLP-1-supported weight loss programme that integrates these treatments with lifestyle modifications for a comprehensive approach to health and well-being. Contact us to explore your options and find out how we can support your journey toward a healthier life.
References
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- U.S. Food and Drug Administration. (2023). FDA approves new drug treatment for chronic weight management, first since 2014. https://www.fda.gov/news-events/press-announcements/fda-approves-new-drug-treatment-chronic-weight-management-first-2014
- UK Government. (2023). MHRA authorises diabetes drug Mounjaro (tirzepatide) for weight management and weight loss. https://www.gov.uk/government/news/mhra-authorises-diabetes-drug-mounjaro-tirzepatide-for-weight-management-and-weight-loss
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