What is the Difference Between Mounjaro and Wegovy? — Weight Loss Advice Bishops Stortford
Mounjaro (tirzepatide) and Wegovy (semaglutide) are both injectable weight loss medications, but they work in different ways and produce different results. Wegovy contains semaglutide, which mimics a single gut hormone — GLP-1 — to reduce appetite and slow digestion. Mounjaro, on the other hand, mimics two gut hormones — GLP-1 and GIP — making it a dual-action medication that clinical trials suggest produces greater average weight loss. Both are administered as weekly injections and are approved for weight management in adults who meet specific clinical criteria. At J E Williamson Pharmacy in Bishops Stortford, we help patients understand which medication may be most appropriate for their individual circumstances, and this is one of the questions we’re asked most frequently.
Finding the right weight loss injection starts with expert advice. Book a consultation with our team at J E Williamson Pharmacy in Bishops Stortford today and get the personalised guidance you need.
Key takeaways
—> Mounjaro targets two hormones (GLP-1 and GIP); Wegovy targets one (GLP-1) — making Mounjaro a dual-action medication.
—> Clinical trials suggest Mounjaro produces greater average weight loss than Wegovy, though individual results vary.
—> Both medications are weekly self-administered injections with similar side effect profiles, primarily gastrointestinal.
—> Wegovy is specifically licensed for weight management in the UK; Mounjaro received its UK weight management licence in 2023.
—> Neither medication is suitable for everyone — eligibility is based on BMI and the presence of weight-related health conditions.
—> The right choice between the two depends on your individual health profile, medical history, and clinical assessment.
How Do Mounjaro and Wegovy Work?
Both medications belong to a class of drugs known as incretin mimetics — they replicate the action of hormones naturally released by the gut after eating. Wegovy works by activating GLP-1 receptors, which slow gastric emptying, reduce appetite, and improve blood sugar regulation. Mounjaro goes a step further by also activating GIP receptors, which play an additional role in fat metabolism and insulin secretion. This dual mechanism is widely believed to be the reason Mounjaro tends to produce greater weight loss in clinical settings.
How Much Weight Can You Lose on Each Medication?
In clinical trials, people taking Wegovy lost an average of approximately 15% of their body weight over 68 weeks. Those taking Mounjaro at the highest dose (15mg) lost an average of around 20–22% of body weight over a similar period — a meaningful difference. It’s important to note, however, that these are averages from controlled trial settings, and real-world results vary significantly depending on diet, lifestyle, dose, and individual metabolic factors. Neither medication is a guaranteed solution, but both represent a significant advance in medically supported weight management.
Choosing between Mounjaro and Wegovy is a decision best made with expert guidance. Our knowledgeable team at J E Williamson Pharmacy is here to help you weigh up your options and make the right choice for your health. Contact our team in Bishops Stortford today and get the clarity you need to move forward with confidence.
Mounjaro vs Wegovy: A Side-by-Side Comparison
The table below breaks down the key differences between Mounjaro and Wegovy to help you understand how the two medications compare.
| Feature | Mounjaro (tirzepatide) | Wegovy (semaglutide) |
|---|---|---|
| Active ingredient | Tirzepatide | Semaglutide |
| Hormone targets | GLP-1 and GIP (dual) | GLP-1 only |
| Administration | Weekly injection | Weekly injection |
| Starting dose | 2.5mg | 0.25mg |
| Maximum dose | 15mg | 2.4mg |
| Average weight loss (trials) | ~20–22% body weight | ~15% body weight |
| UK licence for weight management | Yes (approved 2023) | Yes (approved 2023) |
| Common side effects | Nausea, vomiting, diarrhoea | Nausea, vomiting, diarrhoea |
| Also approved for type 2 diabetes | Yes | No (Ozempic is) |
What are the Side Effects of Weight Loss Medications?
The side effect profiles of Mounjaro and Wegovy are broadly similar, as both act on the GLP-1 pathway. The most commonly reported side effects include nausea, vomiting, diarrhoea, constipation, and reduced appetite — most of which tend to be mild to moderate and improve as the body adjusts to the medication. Both medications are titrated gradually to minimise these effects. Serious side effects are rare but can include pancreatitis, gallbladder issues, and — in those with a personal or family history — a potential risk of thyroid tumours, which is why a thorough medical assessment is essential before starting either treatment.
Who is Eligible for Mounjaro and Wegovy?
In the UK, both medications are indicated for adults with a BMI of 30 or above, or a BMI of 27 or above with at least one weight-related health condition such as type 2 diabetes, hypertension, or high cholesterol. Neither is suitable for people who are pregnant or breastfeeding, those with a personal or family history of medullary thyroid carcinoma, or individuals with certain gastrointestinal conditions. A full clinical assessment is required before either medication is prescribed, which is why seeking advice from a qualified healthcare professional is so important.
Which is Better — Mounjaro or Wegovy?
Based on current clinical evidence, Mounjaro produces greater average weight loss than Wegovy — but “better” is a relative term that depends entirely on the individual. Some patients respond exceptionally well to Wegovy; others find Mounjaro more effective. Factors including your medical history, current medications, and how well you tolerate each drug all play a role in determining which is the right fit. The decision should always be made in consultation with a qualified prescriber who can assess your full health profile.
Medically supported weight loss with Mounjaro or Wegovy could be the turning point you’ve been looking for. Call us now at J E Williamson Pharmacy in Bishops Stortford and let our expert team guide you through your options.
Frequently Asked Questions
Whether you’re weighing up your options or just starting to explore weight loss injections, here are the questions our team at J E Williamson Pharmacy in Bishops Stortford hears most often.
Can I switch from Wegovy to Mounjaro?
It is possible to switch from Wegovy to Mounjaro, but this should only be done under the guidance of a prescribing clinician who can assess whether the switch is appropriate for your health profile. A wash-out period is not typically required, but dosing and titration will need to be carefully managed during the transition.
Is Mounjaro available on the NHS?
Wegovy was approved for use on the NHS in England in 2023 and is being introduced through specialist weight management clinics, though current supply and capacity constraints mean access remains limited. Your GP can advise on eligibility and referral pathways in your area.
Is Wegovy available on the NHS?
The most effective approach is to eat a nutrient-dense, minimally processed diet, engage in regular physical activity, and prioritise consistent sleep each night. Crash dieting or over-exercising is not recommended, as it can trigger metabolic adaptation that ultimately makes weight management harder in the long term.
How long do you stay on Mounjaro or Wegovy?
Both medications are typically intended for long-term use, as weight regain is common when they are stopped — particularly without sustained lifestyle changes. The duration of treatment is determined on an individual basis by your prescriber, taking into account your progress, tolerability, and overall health goals.
Do Mounjaro and Wegovy require a prescription?
Yes — both Mounjaro and Wegovy are prescription-only medications in the UK and cannot legally be supplied without a valid prescription from a registered prescriber. Always obtain these medications through a regulated pharmacy or licensed healthcare provider to ensure safety and authenticity.
Can you take Mounjaro or Wegovy if you have type 2 diabetes?
Mounjaro is licensed both for weight management and for the treatment of type 2 diabetes in the UK, making it a particularly useful option for patients managing both conditions. Wegovy is not licensed for type 2 diabetes, though semaglutide in a lower dose (Ozempic) is — your prescriber can advise on the most appropriate option for your situation.
Your Weight Loss Journey Starts Here
Both Mounjaro and Wegovy represent a significant step forward in medically supported weight management, and the difference between them goes beyond the headline weight loss figures — it comes down to your individual health, lifestyle, and clinical needs. Our expert team at J E Williamson Pharmacy in Bishops Stortford is dedicated to guiding you through your weight loss options and ensuring you have the right support at every stage of your treatment. Getting expert guidance now could be the single most important step you take towards achieving your long-term weight loss goals. Book a consultation and take control of your weight loss journey.
