Wegovy vs Mounjaro: Complete Weight Loss Comparison Guide 2025 | Effectiveness & Costs

August 2025 | Reading time: 8 minutes

The weight loss injection market has transformed dramatically in recent years, with two standout medications leading the charge: Wegovy and Mounjaro. If you’re considering weight loss injections and wondering which option might be best for you, this comprehensive comparison will help you understand the key differences between these revolutionary treatments.

Both medications have shown remarkable results in clinical trials, but they work differently in your body and have distinct advantages. Let’s explore everything you need to know about Wegovy vs Mounjaro to make an informed decision about your weight loss journey.

What Are Wegovy and Mounjaro?

Wegovy: The Dedicated Weight Loss Solution

Wegovy contains semaglutide as its active ingredient and belongs to a class of medications called GLP-1 receptor agonists. Wegovy is a weight-loss medication that has been specifically approved for chronic weight management in adults and adolescents aged 12 and older. It’s also approved to reduce the risk of serious cardiovascular events in adults with obesity or overweight conditions.

The medication works by mimicking the GLP-1 hormone, which naturally regulates appetite and blood sugar levels. When you inject Wegovy, it signals your brain that you’re full, reduces food cravings, and slows gastric emptying, helping you eat less and feel satisfied longer.

Mounjaro: The Dual-Action Powerhouse

Mounjaro contains tirzepatide and represents a breakthrough in weight loss treatment technology. Mounjaro is a Type 2 diabetes medication that’s often prescribed off-label for weight loss. What makes Mounjaro unique is its dual-action mechanism.

Mounjaro is a dual agonist, which means it mimics 2 hormones (glucose‐dependent insulinotropic polypeptide (GIP) and GLP-1). This dual approach targets multiple pathways involved in appetite regulation and glucose control, potentially offering superior weight loss results compared to single-action medications.

Key Differences Between Wegovy vs Mounjaro

FDA Approval and Primary Uses

The most significant difference for wegovy vs mounjaro lies in their official approvals:

• Wegovy: Specifically approved for weight loss and cardiovascular risk reduction
• Mounjaro: Approved for Type 2 diabetes treatment, used off-label for weight loss

Wegovy is prescribed for weight loss and to lower cardiovascular risks. Mounjaro is approved for type 2 diabetes, and doctors may prescribe it off-label for weight loss.

Mechanism of Action: Wegovy vs Mounjaro

While both are injectable medications that help with weight loss, their mechanisms differ:

• Wegovy: Single GLP-1 receptor agonist
• Mounjaro: Dual GIP and GLP-1 receptor agonist

The main difference is that tirzepatide mimics two hormones while semaglutide mimics one. This dual action may contribute to Mounjaro’s potentially superior weight loss effects.

Weight Loss Effectiveness: Which Works Better?

When comparing weight loss results for wegovy vs mounjaro, the evidence suggests Mounjaro may have a slight edge:

Based on the studies that have been carried out, Mounjaro is a more effective weight loss medication than Wegovy. When combined with positive lifestyle changes, patients can expect to lose 21% of their body weight after 18 months of Mounjaro treatment.

Clinical Trial Results: Wegovy vs Mounjaro

Recent studies show impressive results for both medications:

• Mounjaro: Results from clinical studies have shown that people can lose up to 22.5% of their weight with Mounjaro
• Wegovy: up to 17% of their weight with Wegovy

The British Heart Foundation research found that Mounjaro reduced body weight in people with obesity by just over 20 per cent, whereas Wegovy cut it by nearly 14 per cent.

Real-World Results

While clinical trials provide valuable data, real-world results can vary based on individual factors such as:

• Starting weight and BMI
• Adherence to lifestyle changes
• Individual metabolism
• Concurrent health conditions
• Duration of treatment

Both weight loss injections are most effective when combined with a reduced-calorie diet and increased physical activity. Many users also benefit from support programs like weight watchers near me or slimming world groups near me to maximize their results.

Dosing and Administration: Wegovy vs Mounjaro

Wegovy Dosing Schedule

Wegovy only has 1 maintenance dose. The typical dosing progression includes:

• Week 1-4: 0.25mg once weekly
• Week 5-8: 0.5mg once weekly
• Week 9-12: 1.0mg once weekly
• Week 13-16: 1.7mg once weekly
• Week 17+: 2.4mg once weekly (maintenance)

Mounjaro Dosing Schedule

Mounjaro has 3 maintenance doses, offering more flexibility:

• Week 1-4: 2.5mg once weekly
• Week 5-8: 5mg once weekly
• Week 9-12: 7.5mg once weekly (maintenance option 1)
• Week 13-16: 10mg once weekly (maintenance option 2)
• Week 17+: 15mg once weekly (maintenance option 3)

Injection Technique

Both semaglutide and tirzepatide are prescribed as weekly, self-administered injections and are started at the lowest dose. The injection sites for both medications are similar:

• Abdomen (at least 2 inches from the navel)
• Front of the thigh
• Back of the upper arm

Just like the information provided about Mounjaro injection sites, proper rotation between injection areas is crucial to prevent skin irritation and ensure optimal absorption.

NHS Availability

Both medications have limited NHS availability:

• Wegovy is currently only available on the NHS through a specialist weight management service
• Both medicines are used in NHS specialist weight-loss clinics in combination with diet and exercise to aid weight loss

For most people seeking these treatments, private prescriptions remain the primary option, making cost comparison essential for long-term planning.

Side Effects and Safety Considerations

Common Side Effects

Weight-loss jabs such as Wegovy and Mounjaro can have unpleasant side effects, the most common being nausea and vomiting, heartburn, constipation, diarrhoea, stomach pains and headaches, which affect around 10% of people taking them.

Both medications typically cause similar gastrointestinal side effects, including:

• Nausea and vomiting
• Diarrhea or constipation
• Abdominal pain
• Heartburn
• Reduced appetite
• Headaches

Managing Side Effects

The gradual dose escalation for both medications helps minimize side effects. your dose will be increased slowly to minimise your chances of getting them.

Tips for managing side effects include:

• Eating smaller, more frequent meals
• Avoiding fatty or fried foods
• Staying hydrated
• Taking the injection at the same time each week
• Following proper injection site rotation

Serious Considerations

More severe, but rarer side effects reported have included pancreatitis, gallbladder problems, and kidney issues. Both medications carry warnings about potential thyroid tumors based on animal studies, though no causal relationship has been established in humans.

Who Should Consider Each Option?

Wegovy May Be Better For:

• Individuals primarily focused on weight loss
• Those seeking an FDA-approved weight loss treatment
• People with cardiovascular risk factors
• Individuals who prefer a single maintenance dose
• Those looking for established long-term safety data

Mounjaro May Be Better For:

• People with Type 2 diabetes who also want weight loss
• Individuals seeking maximum weight loss potential
• Those who want flexible maintenance dosing options
• People who haven’t achieved desired results with single-action GLP-1 agonists
• Individuals willing to use an off-label treatment for weight loss

Alternatives and Complementary Approaches

While weight loss injections like Wegovy and Mounjaro are highly effective, they work best as part of a comprehensive approach:

Professional Support Services

• Weight Watchers: Look for “weight watchers near me” to find local support groups
• Slimming World: Search “slimming world groups near me” for community-based weight loss support
• NHS Weight Loss Services: Available through GP referrals for eligible patients

Additional Options

• Boots Weight Loss Services: Many high-street pharmacies offer weight management consultations
• Appetite Suppressant UK: Various over-the-counter options available, though less effective than prescription treatments
• Diet Injections: Other prescription options may be suitable for some individuals

Making Your Decision: Key Factors to Consider

When evaluating Wegovy vs Mounjaro, consider these crucial factors:

Effectiveness Priorities

If maximum weight loss is your primary goal, Mounjaro studies have proven that the new injection for weight loss is a little more effective than Wegovy.

Budget Considerations

Mounjaro may offer slightly more significant weight loss due to its dual action but comes at a higher cost. Wegovy is also highly effective and generally less expensive.

Medical History

Your healthcare provider will consider:

• Current medications
• Diabetes status
• Cardiovascular health
• Previous weight loss attempts
• Family medical history

Lifestyle Factors

Consider your ability to:

• Commit to weekly injections
• Follow dietary recommendations
• Engage in regular physical activity
• Attend follow-up appointments
• Manage potential side effects

The Future of Weight Loss Treatments

The success of both Wegovy and Mounjaro has paved the way for continued innovation in weight loss injections. Research continues into new formulations, combination therapies, and alternative delivery methods that may offer even better results with fewer side effects.

As these medications become more established, we can expect:

• Broader NHS availability
• Competitive pricing
• Improved formulations
• Better side effect profiles
• Enhanced patient support programs

Conclusion: Wegovy vs Mounjaro

Both Wegovy and Mounjaro represent significant advances in weight loss treatment, offering hope to millions struggling with obesity. While As the active ingredients are slightly different, you may find that one treatment is better for you or that one causes fewer side effects.

For these reasons, it’s best to work with a healthcare provider to find the most appropriate treatment option. Your doctor can assess your individual circumstances, medical history, and weight loss goals to determine which medication might be most suitable for you.

Remember that these weight loss injections are tools to support your journey, not magic solutions. Success requires commitment to lifestyle changes, including dietary modifications and increased physical activity. Whether you choose Wegovy or Mounjaro, combining treatment with professional support from services like weight watchers near me or slimming world groups near me can significantly enhance your results.

The choice between Wegovy vs Mounjaro ultimately depends on your specific needs, medical history, budget, and weight loss goals. Both offer proven effectiveness in helping people achieve significant, sustainable weight loss when used as part of a comprehensive treatment plan.

Take the first step by consulting with a qualified healthcare provider who can guide you through the decision-making process and help you embark on your weight loss journey with confidence. Contact VIVO Body Studio today and get your consultation today!