Mounjaro vs Wegovy: Comparing the UK’s Most Popular Weight Loss Medications

Maintaining a healthy weight is a key part of overall well-being, but for many adults, losing weight can be a real challenge. Even with balanced eating and regular activity, biological factors such as hormones, insulin resistance, and metabolism can make it difficult to achieve or maintain results.

Two prescription-only treatments, Mounjaro (tirzepatide) and Wegovy (semaglutide), have recently become available in the UK to support adults struggling with obesity or weight-related health conditions. Both medicines work by targeting hormones that regulate appetite and blood sugar, but they aren’t identical.

In this guide, Clockhouse Pharmacy in Romford explains the key differences between Mounjaro vs Wegovy, how they work, and what to consider before starting treatment.

What Are Wegovy and Mounjaro?

Both Wegovy and Mounjaro are injectable prescription medications used alongside a reduced-calorie diet and increased physical activity to support weight management in adults who are either:

—> Obese (BMI ≥30), or

—> Overweight (BMI ≥27) with at least one weight-related condition, such as high blood pressure, type 2 diabetes, or high cholesterol.

Wegovy (semaglutide)

Wegovy contains semaglutide, a medicine that mimics a natural hormone called GLP-1 (glucagon-like peptide-1). This hormone helps control appetite and food intake. By acting on brain receptors that regulate hunger, Wegovy helps you feel fuller for longer, leading to reduced calorie intake and gradual weight loss.

Wegovy is taken once weekly as a self-administered injection under the skin, usually in the thigh, abdomen, or upper arm.

Mounjaro (tirzepatide)

Mounjaro contains tirzepatide, a newer medicine that works on two hormone receptors: GLP-1 and GIP (glucose-dependent insulinotropic polypeptide).
This dual action helps regulate both appetite and blood sugar more effectively, which may contribute to enhanced weight loss results for some people.

Like Wegovy, Mounjaro is injected once weekly under the skin.

How Do They Work?

Both treatments help to:

—> Reduce appetite and hunger levels

—> Slow digestion, keeping you fuller for longer

—> Support healthier blood sugar control

However, Mounjaro’s dual hormone mechanism means it may have a broader effect on metabolism and insulin regulation. Early clinical studies suggest this could translate into greater average weight loss compared with semaglutide, although individual results vary.

It’s important to note that neither medicine is a quick fix. Both should be used as part of a holistic approach that includes nutrition, physical activity, and behavioural support. Weight loss will vary between individuals depending on their starting point and adherence to lifestyle changes.

Wegovy vs Mounjaro: Key Differences

Although both medicines are once-weekly injections used to support weight loss, there are a few important distinctions between them.

Active Ingredient and Hormone Targets

—> Wegovy contains semaglutide, which works on the GLP-1 receptor.

—> Mounjaro contains tirzepatide, which acts on two receptors – GLP-1 and GIP.
This dual action may enhance appetite control and glucose regulation in some patients.

How They Work

Both medicines help reduce hunger, slow digestion, and support steadier blood sugar levels. However, Mounjaro’s dual-hormone effect can influence metabolism more broadly, which may contribute to greater average weight loss in studies.

Dosing

Both treatments are taken as a once-weekly injection under the skin, usually in the abdomen, thigh, or upper arm. Doses are increased gradually over time to help the body adjust and reduce the risk of side effects.

Effectiveness

Clinical trials show that, when combined with lifestyle changes:

—> People using Wegovy lost around 15% of their body weight on average over 68 weeks.

—> People using Mounjaro achieved up to 20% weight loss in similar studies, though results vary from person to person.

While Mounjaro has shown slightly higher average results, it remains a newer treatment. Ongoing research and real-world use will help clarify its long-term safety and effectiveness.

Possible Side Effects and Safety

Both Wegovy and Mounjaro can cause side effects, most commonly nausea, stomach discomfort, constipation, or diarrhoea as the body adjusts. These effects are usually mild to moderate and often lessen over time.

Less common but serious risks include pancreatitis or gallbladder problems, so it’s essential to report any severe or persistent abdominal pain to your clinician or pharmacist.

Neither treatment is suitable for everyone. You should always seek medical advice before starting, particularly if you have:

—> A history of pancreatitis

—> Severe gastrointestinal disease

—> Certain thyroid conditions

Your prescriber will assess your health and determine whether a GLP-1 or dual-action medicine is appropriate.

Wegovy vs Mounjaro: Which Is Better?

There’s no one-size-fits-all answer.

—> Wegovy has been available longer, with extensive clinical data and well-understood effects.

—> Mounjaro offers an innovative dual-hormone mechanism that may deliver enhanced results for some users, but it is newer and still being evaluated in real-world settings.

The best option depends on your medical history, weight loss goals, tolerance to side effects, and professional guidance. A pharmacist or prescriber can help determine which is most suitable based on your individual needs.

Accessing Treatment Safely

Because both medicines are prescription-only, they should only be obtained from a registered healthcare provider or GPhC-registered UK pharmacy. Unregulated online sources or social-media adverts can carry serious risks, including counterfeit or unsafe products.

At Clockhouse Pharmacy in Romford, our trained pharmacists can provide:

—> Professional advice on weight management options

—> Guidance on safe and effective use of prescribed medicines

—> Ongoing support to help you achieve sustainable results

Consultations are discreet, supportive, tailored to your health, and easy to book online.

The Bottom Line

Both Wegovy and Mounjaro represent major advances in medical weight management. They work in similar ways to help reduce appetite and promote gradual, healthy weight loss, but differ in their active ingredients and how they interact with the body.

Whichever option you choose, these treatments work best alongside a healthy diet, regular physical activity, and professional monitoring.

If you’re considering Wegovy or Mounjaro in Romford, speak to the team at Clockhouse Pharmacy for expert, confidential support. We can help you understand your options and begin your weight-management journey safely and effectively.

This blog was written on behalf of Clockhouse Pharmacy by Pharmacy Mentor.