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Ozempic vs. Mounjaro: Side Effects, Costs, and Effectiveness

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Ozempic vs. Mounjaro: Side Effects, Costs, and Effectiveness

The global obesity crisis is escalating, with recent statistics highlighting a concerning trend across the world. According to the World Obesity Federation's World Obesity Atlas 2023, there's a prediction that more than half of the global population will be living with overweight and obesity within the next 12 years if current trends continue and without significant improvements in prevention, treatment, and support. The World Health Organization (WHO) adds more context to this crisis, noting that in 2022, 2.5 billion adults (18 years and older) were overweight, of which 890 million were living with obesity. Remarkably, worldwide adult obesity has more than doubled since 1990, and adolescent obesity has quadrupled. The WHO also reported that 43% of adults aged 18 years and over were overweight and 16% were living with obesity in the same year.

Mounjaro vs Ozempic injection pens

The health consequences of this trend are severe, as obesity is a major risk factor for various diseases, including heart disease, stroke, diabetes, and several types of cancer. Overweight and obesity are largely preventable through lifestyle changes such as diet and exercise, yet the prevalence continues to rise, underscoring the need for more effective public health policies and interventions.

The potential of GLP-1 agonists in this context emerges as a beacon of hope. GLP-1 agonists are a class of medications that mimic the action of the glucagon-like peptide-1 hormone, which is involved in glucose metabolism and appetite regulation. By enhancing the body's natural responses to food intake, these medications can help reduce appetite and food consumption, leading to weight loss. They are increasingly being recognized for their benefits in the management of type 2 diabetes and, by extension, in the treatment of obesity. Given the escalating global obesity crisis, the role of GLP-1 agonists in weight management is garnering significant attention from the medical community and patients alike, marking a promising frontier in the fight against obesity and its associated health consequences.

Mounjaro vs. Ozempic: Key Similarities and Differences

Mounjaro and Ozempic are two drugs that have garnered attention in the medical community for their effectiveness in treating type 2 diabetes and, in some cases, for their weight loss benefits. Despite their shared goals, the drugs have distinct active ingredients, mechanisms of action, and FDA approvals, highlighting their unique positions in the treatment landscape.

Active Ingredients

  • Mounjaro: The active ingredient in Mounjaro is tirzepatide. It is a relatively new addition to the market, designed to address type 2 diabetes and obesity.
  • Ozempic: Ozempic's active ingredient is semaglutide. It has been used for several years not only to treat type 2 diabetes but also, in a different dosage under the brand name Wegovy, for weight management.

Mechanisms of Action

Both Mounjaro and Ozempic are part of a class of drugs that mimic the action of natural hormones in the body to regulate blood sugar levels. However, their mechanisms of action have crucial differences, primarily in how they influence the body's response to glucose.

  • Mounjaro (Tirzepatide): It works by activating both the glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) receptors. This dual action not only stimulates insulin secretion in response to high blood sugar levels but also slows down gastric emptying and reduces appetite, which can lead to weight loss. The inclusion of GIP receptor activation is what sets tirzepatide apart, as it offers a broader approach to managing diabetes and body weight.
  • Ozempic (Semaglutide): Semaglutide primarily targets the GLP-1 receptor, enhancing insulin secretion when glucose levels are high, suppressing glucagon secretion, and also slowing gastric emptying to reduce appetite. While it shares some mechanisms with tirzepatide, the absence of direct GIP receptor activation means its approach is slightly more focused on the GLP-1 pathway.
How GLP-1 Works

Read more: Is Mounjaro Better Than Wegovy?


  • Mounjaro: The FDA approved Mounjaro (tirzepatide) in May 2022 for the treatment of type 2 diabetes. It's recognized for its effectiveness in improving blood sugar control and for providing substantial weight loss benefits, which has sparked interest in its potential off-label use for obesity management.
  • Ozempic: Ozempic received FDA approval in 2017 for the treatment of type 2 diabetes. Its success in improving glycemic control and aiding in weight loss led to the development of a higher-dose formulation, Wegovy, specifically approved for weight management in individuals with obesity or overweight with at least one weight-related condition in 2021.

UK Approvals

In the UK, Mounjaro (tirzepatide) has received approval for weight loss, marking a significant step in addressing obesity and related health conditions. Conversely, Ozempic is approved solely for the treatment of type 2 diabetes, highlighting its role in managing blood sugar levels without the endorsement for weight loss use in this region.

Wegovy, known by its generic name semaglutide, has been approved for use in the UK for weight loss. The National Institute for Health and Care Excellence (NICE) issued guidelines in 2023 recommending Wegovy for prescription to individuals with a body mass index (BMI) usually of 30kg/m^2 and over, who also have at least one weight-related health condition, including those with prediabetes or type 2 diabetes. The guidelines specify that Wegovy should be offered within a specialist weight management service, taking into account personal circumstances and the potential for side effects.

Dosage and Administration

Mounjaro (Tirzepatide)

Injection Frequency: Once weekly
Dosage Increase Over Time: Patients start with a dose of 2.5mg once a week for four weeks. The dose may then be increased to 5mg once a week, with potential further increases in at least 4-week intervals up to the maximum dose of 15mg once weekly, depending on the doctor's recommendation.

Wegovy (Semaglutide)

Injection Frequency: Once weekly
Dosage Increase Over Time: The starting dose is usually lower, and then it is gradually increased over time.

This table includes the cost of each dose level for both Mounjaro (tirzepatide) and Wegovy (semaglutide), with each pen representing a 4-week supply of the medication.

DoseMounjaro (tirzepatide)Wegovy (semaglutide)
Lowest dose2.5 mg0.25 mg
Second dose5 mg0.5 mg
Third dose7.5 mg1.0 mg
Fourth dose10 mg1.7 mg
Fifth dose12.5 mgN/A
Highest dose15 mg2.4 mg

Weight Loss Results

Clinical Trial Findings

Clinical trial findings suggest that Mounjaro (Tirzepatide) might be more effective than Ozempic (Semaglutide) in both blood glucose control and weight loss. A comprehensive analysis of 22 randomised controlled trials involving 18,472 participants with type 2 diabetes presented at the 59th European Association for the Study of Diabetes indicated that all doses of Tirzepatide (5 mg, 10 mg, and 15 mg) were more effective in reducing A1C and body weight compared to the respective doses of Semaglutide (0.5 mg, 1 mg, and 2 mg). Specifically, even the lowest dose of Mounjaro (5 mg) was found to be more effective in reducing body weight than the 1 mg and 0.5 mg doses of injectable Semaglutide​​.

In addition, the SURPASS clinical trial program, which included phase-3 studies evaluating Mounjaro as a monotherapy and as an add-on to standard therapies for type 2 diabetes, demonstrated significant results. Participants treated with Mounjaro experienced an average weight loss of between 12 and 25 pounds, depending on the dosage and co-administered medications. In a head-to-head clinical trial comparing Mounjaro to Ozempic, Mounjaro was shown to be more effective at lowering HbA1c levels and reducing body weight over a period of 40 weeks. Specifically, the reductions in HbA1c levels with Mounjaro doses were 2.01% (5 mg), 2.24% (10 mg), and 2.30% (15 mg), compared to a reduction of 1.86% with Ozempic (1 mg). Mean body weight reductions were 17, 21, and 25 pounds for Mounjaro, compared to 13 pounds for Ozempic​​.

How quickly do you lose weight on Mounjaro?

As for how quickly one might expect to lose weight on Mounjaro, it's important to note that individual results vary significantly based on a variety of factors including the dose, the individual's baseline weight, their diet, exercise habits, and overall health. The clinical trials indicate significant weight loss can occur within the trial periods of up to 52 weeks, but individual experiences will differ. It's also crucial to approach weight loss with realistic expectations and in consultation with a healthcare provider to ensure a safe and effective treatment plan. 

Given these findings, Mounjaro appears to offer a promising option for individuals looking to manage type 2 diabetes and achieve weight loss. However, it's essential to remember that the ultimate treatment choice should be based on a comprehensive evaluation of the patient's condition, treatment goals, and potential risks and benefits of the medication, possibly taking into account additional factors such as cost and the long-term impact on health.

Ozempic (Semaglutide/Wegovy)  and Cardiovascular Benefits

Recently Novo Nordisk's Wegovy has been acknowledged by the FDA for its cardiovascular benefits, marking a significant endorsement for the medication. In pivotal clinical trials, Wegovy demonstrated its capacity to lower the risk of major cardiovascular events, such as heart attacks and strokes. This recent FDA approval specifically targets individuals who are overweight or obese and are simultaneously managing cardiovascular disease, highlighting Wegovy's dual role in supporting weight management and cardiovascular health.

Side Effects: What to Expect

Common Side Effects

Both medications, being part of the GLP-1 receptor agonist class, share similar common side effects due to their mechanism of action, which involves affecting glucose control and weight management. Common side effects include:

  • Nausea
  • Diarrhea
  • Vomiting
Mounjaro side effects infographics

These side effects are quite prevalent when therapy is initiated or when the dose is adjusted, with a significant portion of patients experiencing them at some point during their treatment. However, these symptoms are generally temporary and tend to subside as the body adjusts to the medication.

Serious but Rarer Concerns

Though less common, there are serious concerns associated with these medications that patients should be aware of:

  • Pancreatitis
  • Gallbladder issues

Patients are advised to watch for and report symptoms such as severe abdominal pain, nausea, vomiting, or symptoms indicative of gallbladder problems like jaundice. These conditions require immediate medical attention.

For the most up-to-date Mounjaro or Wegovy side effects, check your patient information leaflet.

Cost Considerations

Both Mounjaro and Wegovy, alternatives for weight loss that mimic the same hormone as Ozempic, are available through the eMed Weight Management Programme from £189 per month. This program provides a comprehensive approach to weight management, including the medications themselves, monthly clinical reviews, weekly check-ins, and progress monitoring, all tailored to assist individuals in achieving their weight loss goals. Medications are delivered directly to the participants, ensuring convenience and continuity in treatment. This pricing represents a significant opportunity for those seeking to manage their weight with the support of these advanced treatments.

Read more: Where Can I Buy Mounjaro in the UK

Who Is the Ideal Candidate?

For those exploring weight loss options, Mounjaro and Wegovy (Ozempic alternative) offer effective solutions, both being injectable treatments approved and available in the UK. These treatments are tailored to each individual's health profile, including medical history, ongoing medications, and Body Mass Index (BMI). The eligibility criteria for these weight loss injections are as follows:

  • A BMI of 30 kg/m² or above, categorising an individual as obese.
  • A BMI of 27 kg/m² or above (classified as overweight) coupled with weight-related health conditions such as pre diabetes or hypertension.

These guidelines underscore the critical role of comprehensive lifestyle changes in conjunction with medication for managing type 2 diabetes and obesity. Lifestyle modifications, including diet and exercise, remain foundational to achieving and maintaining weight loss and improving blood glucose control, enhancing the effectiveness of medications like tirzepatide and Ozempic.

Through the eMed Weight Management Programme, obtaining Mounjaro or Wegovy is streamlined, ensuring prescriptions are accessible to those meeting the criteria. This program provides a comprehensive approach to weight management, incorporating these advanced treatment options alongside dietary and lifestyle modifications for optimal health outcomes. For more information on accessing these treatments and to discuss your eligibility, the eMed Weight Management Programme is your dedicated resource for a tailored weight loss journey.

Beyond the Medications: Key Reminders

Embarking on a weight loss journey can often feel like navigating through a maze blindfolded. Amidst the clamour for quick fixes and miracle cures, it's crucial to anchor our expectations and efforts in reality and knowledge. Here are some heartfelt reminders to guide you through this voyage, ensuring you feel supported, understood, and above all, empowered to make lasting changes.

Realistic Expectations: The Unsung Hero of Weight Loss

Let's set the stage straight - weight loss is more marathon than sprint. It's about incremental wins and learning from setbacks. Expecting immediate and dramatic results from medications like Mounjaro or Wegovy without considering the holistic picture can set us up for disappointment. Remember, these medications are not magical potions but tools designed to complement your efforts. Patience, persistence, and a dash of self-compassion can make this journey not just successful, but also enriching.

The Role of Medical Supervision: Your Compass and Map

Navigating through the weight loss terrain without a compass is akin to setting sail without a map. Just as every explorer needs guidance, your journey requires the expertise of healthcare professionals. They're not just gatekeepers to prescriptions but invaluable allies who tailor treatments to your unique health profile, monitor progress, and adjust sails as needed. Regular check-ins ensure that your voyage is not just effective but also safe.

Lifestyle as the Foundation: Building Your Ship

People who can switch to Wegovy

If medications are the wind in your sails, lifestyle changes are the ship itself. Sturdy and well-built, capable of weathering storms. A balanced diet, regular physical activity, and sufficient sleep form the keel and hull of this ship, providing resilience against the waves of cravings and setbacks. Integrating these habits might seem daunting at first, but with each small change, you fortify your vessel, making your journey smoother and more enjoyable.

Embarking on this journey requires courage, commitment, and a clear understanding that the real transformation begins within. Medications like Mounjaro and Wegovy can offer a boost, but the essence of sustainable weight loss lies in nurturing a lifestyle that supports your physical and mental well-being. Remember, the goal is not just to reach the destination but to thrive along the way and beyond.

So, as you step forward, do so with the knowledge that while the path may be challenging, it's also ripe with opportunities for growth and self-discovery. Here's to navigating the waves of change with grace, strength, and a sense of adventure.


Can I take these medications if I have other health conditions?

Both Wegovy and Mounjaro should be used with caution if you have other health conditions. It's important to consult with your healthcare provider to review your medical history and current health status to determine if these medications are safe for you. They may adjust dosages or suggest alternative treatments based on other conditions you have.

How quickly will I see weight loss results?

The timeline for seeing weight loss results can vary. Some individuals may start to see results within the first few weeks of treatment, while for others, it may take longer. Consistency with the medication, alongside dietary changes and exercise, plays a critical role in how quickly you'll see results.

Is Wegovy or Mounjaro more effective?

Both medications have shown effectiveness in clinical trials, with Mounjaro leading to an average weight loss of up to 22.5%, and Wegovy up to 15% of body weight. The effectiveness can vary based on individual factors, including adherence to the medication regimen, lifestyle changes, and individual biology.

Can I switch from Wegovy to Mounjaro?

Yes, switching between the two is possible. Read more here about switching from Ozempic to Mounjaro.

Is Wegovy or Mounjaro more expensive?

When comparing their costs, it's essential to consider dosage and the source of purchase. While there might be a slight variance in the starting dose prices, the costs typically balance out at maintenance doses. Consulting our healthcare provider or pharmacist can provide you with a more precise insight into the expenses associated with each option.

eMed Weight Management Programme

eMed Weight Management Programme

If you're looking to explore further options for weight management, consider checking out the eMed Weight Management Programme. Designed to support individuals in achieving their health goals, this program offers personalised guidance and resources tailored to your specific needs. Whether you're considering Ozempic or Mounjaro, eMed's comprehensive approach can provide you with the support and tools you need to make informed decisions about your health journey. Take the next step towards a healthier you with the eMed Weight Management Programme.


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  • Electronic Medicines Compendium (EMC). (2024). "Mounjaro 2.5/5/7.5/10/12.5/15mg KwikPen: Formulation and Administration Guidance." Retrieved from on February 15, 2024.
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  • National Health Service (NHS). (Year Unknown). "Obesity Treatment: Guidelines and Interventions." Retrieved from on February 15, 2024.
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  • PubMed. (Year Unknown). "Clinical Outcomes of Semaglutide Treatment in Patients with Obesity: A Longitudinal Study." Retrieved from on February 15, 2024.
  • Saxenda. (Year Unknown). "Saxenda (Liraglutide) Dosing Schedule and Administration Guidance." Retrieved from on February 15, 2024.
  • Wegovy. (Year Unknown). "Frequently Asked Questions (FAQ) about Wegovy: Patient Education and Support." Retrieved from on February 15, 2024.
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The information provided is for educational purposes only and is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Seek the advice of a doctor with any questions you may have regarding a medical condition. Never delay seeking or disregard professional medical advice because of something you have read here.

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