If you're researching weight loss injections in the UK, you've almost certainly come across two names: Mounjaro and Wegovy. Both have transformed how we approach weight management — but they're not the same, and the right choice depends on you.
As a GPhC-registered pharmacy in Liverpool, we help patients make this exact decision every week. Here's an honest, jargon-free comparison.
The quick answer
Both Mounjaro and Wegovy are clinically proven, prescription-only weight loss injections taken once a week. The headline difference: Mounjaro (tirzepatide) tends to produce greater average weight loss, while Wegovy (semaglutide) has been available longer with a very well-established safety record. Both require a proper medical assessment before you start — which is exactly what a pharmacist consultation provides.
How they work
Both medications mimic hormones your body naturally produces to control appetite and blood sugar:
- Wegovy (semaglutide) targets one hormone pathway — GLP-1. It slows how quickly your stomach empties and reduces appetite, so you feel fuller for longer.
- Mounjaro (tirzepatide) targets two hormone pathways — GLP-1 and GIP. This dual action is why many patients see stronger results.
Results: what the studies show
In clinical trials, the average weight loss over roughly 16 months was:
- Wegovy: around 15% of body weight
- Mounjaro: around 20% of body weight at the highest dose
That said, "average" is the key word. Your results depend on your starting point, diet, activity, and how your body responds. Some people do brilliantly on Wegovy; others need Mounjaro's dual action. This is why a personalised assessment matters far more than a headline number.
Side effects
Both medications share similar side effects, especially in the first few weeks as your body adjusts:
- Nausea
- Reduced appetite
- Digestive changes
- Tiredness
These usually settle as your dose is gradually increased. A good weight management service starts you on a low dose and steps you up slowly — which dramatically reduces side effects. Never start either medication without medical supervision.
Cost in the UK
Both are available privately in the UK. Pricing depends on the dose and provider, and typically increases as your dose steps up over the first few months. Rather than chasing the cheapest possible price online — where safety and follow-up are often missing — we recommend a provider who includes a proper consultation, ongoing monitoring, and pharmacist support in the price. That's what keeps you safe and gets you results.
Which one is right for you?
Honestly? It depends on factors only a clinical assessment can determine — your BMI, medical history, current medications, and goals. Both are excellent treatments. The mistake people make is choosing based on a headline number rather than what's right for their body.
Start safely with a Liverpool pharmacist
At Anfield Pharmacy, our private weight management service includes a full medical screening, a personalised recommendation between Mounjaro, Wegovy, and other options, and ongoing pharmacist support throughout your journey — all in a confidential, judgment-free setting.
We're a GPhC-registered pharmacy (No. 9010376) on Oakfield Road, trusted by thousands of Liverpool patients. Book your confidential consultation today.
📞 Call 0151 263 3631 or visit us at 140 Oakfield Road, Liverpool L4 0UQ.
This article is for information only and is not medical advice. Mounjaro and Wegovy are prescription-only medicines that require a medical assessment. Suitability is determined on an individual basis.
