With the rise of medical weight loss treatments, Mounjaro and Wegovy have become two of the most talked-about injectable medications in the UK. Both can deliver impressive weight loss results but they’re not the same.
If you’re deciding between them, understanding how they work, their effectiveness, and their side effects can help you make an informed choice.
Here’s everything you need to know about Mounjaro vs Wegovy before you buy.
What Are Mounjaro and Wegovy?
Both Mounjaro and Wegovy are injectable prescription medications that help control appetite and support weight loss.
They belong to a class of medicines known as GLP-1 receptor agonists, which mimic natural hormones that regulate hunger and blood sugar.
The key difference lies in how many hormones each one targets:
| Medication | Active Ingredient | How It Works |
|---|---|---|
|
Mounjaro
|
Tirzepatide
|
Mimics two hormones — GLP-1 and GIP — to control blood sugar, reduce appetite, and boost metabolism.
|
|
Wegovy
|
Semaglutide
|
Mimics GLP-1 only — helps regulate appetite and slow digestion to make you feel fuller for longer.
|
Both are taken as a once-weekly injection, alongside a healthy diet and regular exercise.
How They Work in the Body
| Mechanism | Mounjaro (Tirzepatide) | Wegovy (Semaglutide) |
|---|---|---|
|
Hormones targeted
|
GLP-1 and GIP
|
GLP-1 only
|
|
Appetite reduction
|
Very strong
|
Strong
|
|
Metabolism boost
|
Yes – through dual hormone action
|
Moderate
|
|
Blood sugar control
|
Excellent
|
Excellent
|
|
Energy regulation
|
Enhanced
|
Improved
|
Mounjaro’s dual-hormone mechanism gives it a potential edge in weight loss and metabolic effects, while Wegovy remains a clinically proven, well-established option with a strong safety profile.
Weight Loss Results: Mounjaro vs Wegovy
Both medications have shown impressive weight loss results in clinical trials, but Mounjaro tends to achieve slightly greater reductions.
- Wegovy (semaglutide):
Average weight loss of around 10–15% of total body weight over 68 weeks. - Mounjaro (tirzepatide):
Average weight loss of 15–22% of total body weight over a similar timeframe, depending on the dose.
Results vary between individuals, and both medications work best when combined with healthy nutrition, regular activity, and ongoing medical support.
Side Effects: What to Expect
Both Mounjaro and Wegovy have similar side effects, most of which are mild and improve as your body adjusts.
| Common Side Effects | Mounjaro | Wegovy |
|---|---|---|
|
Nausea
|
✔️
|
✔️
|
|
Vomiting
|
✔️
|
✔️
|
|
Diarrhoea
|
✔️
|
✔️
|
|
Constipation
|
✔️
|
✔️
|
|
Indigestion
|
✔️
|
✔️
|
|
Fatigue
|
✔️
|
✔️
|
|
Decreased appetite
|
✔️
|
✔️
|
Less common but serious side effects (rare for both):
- Severe abdominal pain (possible pancreatitis)
- Allergic reactions
- Low blood sugar (especially if used with diabetes medication)
To reduce side effects, both medications are started on a low dose and increased gradually over several weeks.
Mounjaro vs Wegovy: Comparison Summary
| Feature | Mounjaro (Tirzepatide) | Wegovy (Semaglutide) |
|---|---|---|
|
Hormones targeted
|
GLP-1 + GIP
|
GLP-1
|
|
Weight loss potential
|
Up to ~22%
|
Up to ~15%
|
|
Appetite suppression
|
Very strong
|
Strong
|
|
Blood sugar control
|
Excellent
|
Excellent
|
|
Injection frequency
|
Weekly
|
Weekly
|
|
Best for
|
Significant weight loss or metabolic issues
|
Clinically approved medical weight loss
|
|
Typical duration
|
Ongoing (long-term use)
|
Ongoing (long-term use)
|
Both medications are highly effective, but suitability depends on your health, weight loss goals, and how your body responds. Your prescriber can help you determine the best option for your needs.
Final Thoughts
Both Mounjaro and Wegovy represent major advances in medical weight loss, helping thousands of people across the UK achieve sustainable results.
While Wegovy is currently the officially licensed weight-loss medication, Mounjaro’s unique dual-hormone formula offers even greater promise for the future of weight management.
Whichever you choose, combining your treatment with a balanced diet, regular activity, and professional support will help you achieve long-lasting success.
Ready to begin your medical weight loss journey?
DoseDirect offers clinically prescribed Mounjaro and Wegovy treatments, with discreet home delivery and expert support every step of the way.
