Mounjaro vs. Wegovy – Which Weight Loss Injection is More Effective?

Nearly 30% of UK adult population is affected by obesity, creating a high demand for innovative weight management solutions. In the quest for effective weight loss solutions, injections like Mounjaro and Wegovy have emerged as prominent players. These treatments have gained attention for their role in managing obesity, a growing health concern globally.

Is Mounjaro equivalent to Wegovy? Although they are both weight loss drugs powered by similar mechanisms influencing appetite regulation but they are not exactly the same. 

In this comprehensive guide, we’ll delve into the specifics of these medications, comparing their efficacy, safety profiles, mechanisms of action, and user experiences to determine which might be the best choice for your weight loss journey.

Key Takeaways 

– Wegovy is made by Novo Nordisk and contains the active ingredient Semaglutide, whereas

– Mounjaro is produced by Eli Lilly and contains Tirzepatide.

– Both weight loss injections can be obtained via prescription only. 

– Mounjaro has Tirzepatide and Wegovy has Semaglutide, and they work differently. Mounjaro activates both GLP-1 and GIP receptors, while Wegovy only activates the GLP-1 receptor.

Clinical trials suggest that Mounjaro leads to more weight loss compared to Wegovy. On average, patients using Mounjaro lose about 25% of their weight after one year, while those on Wegovy lose around 16%.

Mounjaro Vs. Wegovy: Differences

Mounjaro (Tirzepatide) and Wegovy (Semaglutide) have been the talk of the town since they were launched in the UK. Wegovy was launched in September 2023. However, Mounjaro has recently been approved in the UK by MHRA for chronic weight management. 

Wegovy vs Mounjaro

Active Ingredients

Wegovy, or Semaglutide, functions primarily through the GLP-1 receptor agonism pathway. By mimicking GLP-1, it slows gastric emptying, induces satiety, and leads to a substantial decrease in appetite and caloric intake.

Mounjaro, known generically as Tirzepatide, is not only a GLP-1 receptor agonist but also incorporates the effects of GIP (Glucose-dependent Insulinotropic Polypeptide). This dual-action approach is designed to enhance weight loss by improving insulin secretion, reducing hunger, and potentially improving metabolic efficiency.

Although these weight loss injections contain different active ingredients, they have some similar characteristics and the potential to achieve similar goals in your weight loss journey.

Dosing Schedules

The other major difference between Wegovy and Mounjaro is the dosing schedules.

Wegovy is available in five different strengths, and you take one dose each week. Every four weeks, your Wegovy dose is increased until you reach the maintenance dose. This final dose, which is usually either 1.7mg or 2.4mg, will be determined by your GP.

The clinical licensing for Wegovy clearly states that doses must be increased each month until the maximum 2.4 mg maintenance dose is reached.

All Wegovy doses include:

– 0.25mg

– 0.5mg

– 1mg

– 1.7mg

– 2.4mg

Mounjaro is slightly different because it has 6 different doses: 

2.5 mg, 

5 mg

7.5mg

10mg

12.5mg

15 mg.

Mounjaro has 3 different maintenance dosages – 5 mg, 10 mg and 15 mg. However, only two Mounjaro dosages i.e. 2.5 mg and 5 mg are currently available at The Care Pharmacy.

This means there’s currently more flexibility with Mounjaro’s dosing schedules than Wegovy. 

If you feel you are getting good weight-loss results at a lower maintenance dose of Mounjaro (e.g. 5 mg or 10 mg), you don’t need to increase the dose further.

Mounjaro also has ‘escalation’ doses, which you’ll be required to take for four weeks if you decide to move up from one maintenance dose to another.

For example, if your current maintenance dose is 5 mg and you want to move up to a 10mg maintenance dose, you’ll need to spend 4 weeks on the 7.5 mg escalation dose.

Side Effects

Wegovy’s side effects may include:

  • Gastrointestinal problems – nausea, vomiting, diarrhoea etc, especially when starting treatment
  • Appetite changes
  • Injection site reactions – redness, swelling, pain

Less common but serious risks involve pancreatitis, gallbladder problems, low blood sugar in diabetics on other medications, kidney dysfunction, and potential thyroid C-cell tumour risk.

Common side effects associated with Mounjaro include:

  • gastrointestinal disturbances such as nausea, diarrhea, and vomiting, as well as potential risks of thyroid C-cell tumors. 
  • Tirzepatide seems to be more effective at supporting weight loss than Semaglutide but has a poorer safety profile.

Talk to your healthcare provider about any side effect that bothers you or doesn’t go away.

What is More Effective, Mounjaro or Wegovy?

Mounjaro works better than Wegovy for weight loss. In a 72-week study, 96% of people on the highest dose of Manjaro lost at least 5% of their initial weight. In a similar study, 84% of those taking the highest dose of Wegovy achieved the same weight loss.

While both drugs can lead to significant weight loss, it’s also important to remember that the extent of effectiveness can vary based on individual factors such as body mass index (BMI), existing health conditions and adherence to the treatment plan. 

Can I switch from Wegovy to Mounjaro?

You can switch from Wegovy to Mounjaro, but they’re not interchangeable, which means they can’t be used simultaneously.

Additionally, if you replaced Wegovy with Mounjaro, you might need to start at the lowest dose of Mounjaro and gradually titrate up to the higher doses.

This will depend on your current situation and whether our clinical team determines which dose is safe for you to transition to.

For example, if you’re on 2.4 mg of Wegovy (the highest dose) and switched to Mounjaro, you might have to start on the lowest dose of Mounjaro, 2.5 mg.

However, our clinical team might determine that 5 mg of Mounjaro is safe for you to transition to if your current situation allows it.

Is Mounjaro Available in the UK?

Yes, Mounjaro (Tirzepatide) is available in the UK. It has been approved by the Medicines and Healthcare products Regulatory Agency (MHRA) for both weight management and as a treatment for type 2 diabetes. For weight management, it can be used by adults with a Body Mass Index (BMI) of 30 kg/m² or more, or those with a BMI of 27-30 kg/m² who have weight-related health conditions like prediabetes, high blood pressure, high cholesterol, or heart disease.

You can buy Mounjaro online after an online consultation with our healthcare professionals at The Care Pharmacy. 

Medically reviewed by

Mohammed Lakhi

Superintendent Pharmacist

Muhammad Lahki
The Care Pharmacy

Orforglipron (Foundayo) UK: The New Weight Loss Pill Explained

Clinically reviewed by Mohammed Ismail Lakhi, MPharm — Superintendent Pharmacist (GPhC reg. 2072815) Last updated: April 2026 Key points at a glance Orforglipron (brand name Foundayo) is the first small-molecule GLP-1 weight loss pill, developed by Eli Lilly — the same company behind Mounjaro. It received FDA approval on 1 April 2026 in the United […]

Read More

Wegovy vs Mounjaro (2026): Which Weight Loss Injection Is Right for You?

The most common question we hear from patients is: Wegovy vs Mounjaro — which one should I choose? This honest, pharmacist-written guide covers clinical trial data, the new Wegovy 7.2mg dose, real-world UK pricing, side effects, NHS access, and how to decide which weight loss injection suits your goals. Updated: March 2026 · 16 min […]

Read More

The Difference Between Wegovy and Mounjaro Explained by a Professional: Which is Best to Use During Ramadan?

Wegovy and Mounjaro are two popular injectable weight loss treatments that work by regulating appetite and supporting reduced calorie intake. As their use has grown in the UK, many patients want to understand the differences between them and whether one may be better suited to fasting during Ramadan. Regulated access to both treatments is available […]

Read More

Why Am I Not Losing Weight on Mounjaro? 7 Reasons Weight Loss Can Stall

Mounjaro has quickly become one of the most widely discussed medical weight loss treatments in the UK. Many patients experience noticeable appetite reduction and steady progress during the early stages of treatment. However, it is also very common to reach a point where weight loss slows down or temporarily stops, leading to frustration and the […]

Read More

Xenical Tablets vs Weight Loss Injectables: What Will Work Best For Me?

If you are exploring prescription weight management options and wondering whether Xenical or a weight loss injectable is right for you, our clinical team can help. At The Care Pharmacy, we offer a range of medically approved weight loss treatments, including Xenical and several injectable options. The right choice depends on your health profile, weight […]

Read More

How Saxenda Works Alongside Ramadan For UK Users

If you are using Saxenda in the UK and planning to fast during Ramadan, it is important to understand how to manage your treatment safely. Our pharmacy team can review your situation and help you make informed decisions. Ramadan brings changes to meal timing, hydration, sleep, and daily routine. For Saxenda users, these changes can […]

Read More
icon
UK-Prescribing Pharmacists
icon
No GP Appointments Needed
icon
Fast & Discreet Delivery