Comparisons · 8 March 2026 · 10 min read

Ozempic vs Wegovy vs Mounjaro — Which Is Best for Weight Loss UK? (2026)

Mounjaro leads on weight loss at ~22.5%, but Wegovy's new 7.2mg dose is catching up at ~20.7%. Ozempic isn't licensed for weight loss. Here's how they compare on results, side effects, cost and heart health.

Last updated: March 2026 | glp1guide.live

If you've been trying to figure out the difference between Ozempic, Wegovy and Mounjaro, you're not alone. These three names come up constantly — in Facebook groups, on TikTok, at the GP — but the actual differences between them are rarely explained clearly.

Here's the honest breakdown, based on the latest clinical evidence available in 2026.

The Quick Answer

• Mounjaro is currently the most effective weight loss injection, with average results of around 20–22% body weight lost
• Wegovy is close behind — especially the new 7.2mg dose approved in January 2026, which achieves around 20.7% weight loss
• Ozempic is NOT licensed for weight loss in the UK. It's a diabetes drug. People use it off-label but it's less effective and harder to access for this purpose

What Are They, and How Do They Work?

All three are injectable medications that mimic hormones your body naturally produces after eating. They slow down digestion, reduce appetite, and make you feel fuller for longer.

Wegovy and Ozempic both contain the same active ingredient — semaglutide. They work by mimicking one hormone called GLP-1.

Mounjaro contains tirzepatide, which mimics two hormones — GLP-1 and GIP. This dual action is why it tends to produce stronger results.

Think of it this way: Wegovy and Ozempic push one lever. Mounjaro pushes two.

Weight Loss Results: How Do They Compare?

The gap between Mounjaro and Wegovy has narrowed significantly since January 2026, when the higher-dose Wegovy 7.2mg was approved in the UK. At that dose, results are almost identical to Mounjaro.

In real-world UK data, patients on Wegovy with dietitian coaching achieved 19.1% average weight loss at 12 months — showing that support alongside the medication makes a big difference.

Ozempic for Weight Loss — The Honest Truth

Ozempic is NOT licensed for weight loss in the UK. It's approved for type 2 diabetes management only.

You may have seen it talked about as a weight loss drug online — and it does cause weight loss as a side effect — but:

• The dose is lower than Wegovy (max 2mg vs Wegovy's 2.4mg or 7.2mg)
• No UK clinic can legally prescribe it for weight loss
• If you're seeing it offered this way, be cautious

If you want semaglutide for weight loss, Wegovy is the right medication — same active ingredient, higher dose, and actually licensed for what you're trying to do.

Side Effects: Are They Different?

Side effects are similar across all three — mostly digestive:

• Nausea
• Vomiting
• Constipation or diarrhoea
• Stomach cramps
• Fatigue (especially early on)

These typically happen during the dose escalation phase and improve over time.

One difference: Wegovy has a slightly lower rate of people stopping treatment due to side effects compared to Mounjaro (roughly 4% vs 6–8.5%). So Wegovy may be slightly better tolerated for some people.

Read our full guide on how to manage Ozempic side effects.

Heart Health: One Important Difference

Wegovy has proven cardiovascular benefits. The SELECT trial showed semaglutide reduces the risk of heart attack, stroke, or cardiovascular death by 20% in people with existing heart disease and obesity.

Mounjaro does not yet have this evidence — trials are underway but results aren't confirmed yet.

If you have a history of heart disease, this could tip the decision in favour of Wegovy.

Cost Comparison UK 2026

Since Mounjaro's price increase in September 2025, Wegovy is now the more affordable option for most people.

Read our full Wegovy cost breakdown UK 2026.

NHS Access

Both Wegovy and Mounjaro are available on the NHS — but access is very restricted.

You'll need:

• BMI of 35+ (or 32.5+ for certain ethnic groups)
• At least one weight-related health condition
• GP referral to a specialist Tier 3 weight management service

In Wales, Scotland and Northern Ireland, NHS prescriptions are free. In England, you pay £9.90.

Waiting lists can be 12 months or longer. Most people go private.

So Which One Should You Choose?

Choose Mounjaro if:

• You want maximum weight loss and the higher price is manageable
• You've tried Wegovy and want stronger results
• You don't have a history of heart disease

Choose Wegovy if:

• You want strong results at a lower monthly cost
• You have existing heart disease (proven cardiovascular benefits)
• You want to try the new 7.2mg dose for results comparable to Mounjaro

Don't use Ozempic for weight loss — it's not licensed for this purpose in the UK.

How to Get Started

Both are prescription-only. Online clinics are the most popular route — no waiting lists, quick approval, pen delivered to your door.

See our guide to the best UK online clinics for Wegovy and Mounjaro.

Quick Summary

• Most effective overall: Mounjaro (~22.5% weight loss)
• Best value for money: Wegovy (cheaper since Mounjaro's price rise)
• Best for heart health: Wegovy (proven 20% reduction in cardiovascular events)
• Ozempic for weight loss: Not licensed in the UK — use Wegovy instead
• New in 2026: Wegovy 7.2mg now matches Mounjaro on weight loss results
• Bottom line: Both are excellent — right choice depends on budget, health history and goals

This article is for informational purposes only and does not constitute medical advice. Always consult a UK-registered healthcare professional before starting any prescription medication.

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