Monj / What is Mounjaro / Mounjaro vs Ozempic
Independent comparison, cited trials, live prices
Mounjaro vs Ozempic: licence, weight loss and cost in the UK
Mounjaro and Ozempic are both weekly injections, from two different makers, with two different UK licences. This page sets out the trial where they met head to head, what each is licensed for, the side effects you can expect and what Mounjaro costs today.
- By Nick Johnson, Independent Prescription Pricing Analyst
- Trial figures from peer reviewed papers
- Live prices from GPhC registered pharmacies
- No pharmacy pays for a place
Mounjaro vs Ozempic: the short answer
Mounjaro (tirzepatide) holds a UK licence for weight management and for type 2 diabetes. Ozempic (semaglutide) holds a UK licence for type 2 diabetes only, so a UK pharmacy following the licence will not supply Ozempic for weight loss. In SURPASS-2, the one trial to test the two head to head, people with type 2 diabetes lost 11.2kg on tirzepatide 15mg over 40 weeks, against 5.7kg on semaglutide 1mg. If you want a weekly injection for weight loss, your licensed options are Mounjaro or Wegovy, the weight loss brand of semaglutide.
Mounjaro and Ozempic side by side
| Feature | Mounjaro | Ozempic |
|---|---|---|
| Active ingredient | Tirzepatide | Semaglutide |
| How the medicine acts | Acts on two gut hormone receptors, GIP and GLP-1 | Acts on one gut hormone receptor, GLP-1 |
| Maker | Eli Lilly | Novo Nordisk |
| How you take the medicine | Once a week, KwikPen holding four doses | Once a week, pre-filled pen |
| Dose steps | 2.5mg, 5mg, 7.5mg, 10mg, 12.5mg, 15mg | 0.25mg to start, then 0.5mg, 1mg and 2mg |
| UK licence | Weight management and type 2 diabetes | Type 2 diabetes only |
| NHS route | NICE TA1026 for weight, NICE TA924 for type 2 diabetes | Type 2 diabetes care on the NHS |
| Private supply for weight loss | Yes, after a consultation with a GPhC registered pharmacy | No, weight loss sits outside the licence |
| Weight loss brand from the same maker | Mounjaro covers both uses | Wegovy (semaglutide up to 2.4mg, and 7.2mg) |
Most confusion comes from the last row. Ozempic and Wegovy contain the same molecule. Novo Nordisk sells semaglutide for weight management under the Wegovy name, at higher doses and under a separate licence. Lilly sells tirzepatide under one name, Mounjaro, for both diabetes and weight management. For how the gap between the two semaglutide brands plays out, see our sister site’s Wegovy vs Ozempic guide.
SURPASS-2: the head to head trial
SURPASS-2 randomised 1,879 adults with type 2 diabetes, all already taking metformin, to tirzepatide 5mg, 10mg or 15mg, or to semaglutide 1mg, for 40 weeks. FrÃas and colleagues published the results in the New England Journal of Medicine in 2021.
Every tirzepatide dose beat semaglutide 1mg on both blood sugar and weight. The lower doses produced 7.6kg (5mg) and 9.3kg (10mg) of weight loss. Three limits apply before you read these numbers as a verdict on weight loss:
- Everyone in the trial had type 2 diabetes. People with diabetes tend to lose less weight on these medicines than people without.
- The semaglutide arm stopped at 1mg. Ozempic now goes to 2mg, and Wegovy to 2.4mg and 7.2mg.
- Eli Lilly funded the trial and participants knew which medicine they took.
Weight loss without diabetes
For people without diabetes, the fair comparison is Mounjaro against Wegovy, because Wegovy is the licensed semaglutide for weight management.
| Trial | Medicine and dose | Result |
|---|---|---|
| SURMOUNT-1, 72 weeks | Tirzepatide 15mg | 20.9% lost, against 3.1% on placebo |
| STEP 1, 68 weeks | Semaglutide 2.4mg (Wegovy) | 14.9% lost, against 2.4% on placebo |
| SURMOUNT-5, 72 weeks, head to head | Tirzepatide 10mg or 15mg vs semaglutide 2.4mg | 20.2% lost vs 13.7% lost |
Ozempic doses sit below the Wegovy doses used in these trials. A doctor who wants semaglutide for weight management in the UK prescribes Wegovy. The full weight loss picture across every licensed option, including tablets, is on which GLP-1 is best for weight loss.
Heart and kidney evidence
Ozempic has the longer outcome record in type 2 diabetes. In SUSTAIN-6 (Marso and colleagues, NEJM 2016), semaglutide cut the risk of heart attack, stroke or cardiovascular death by 26% in people with type 2 diabetes at high cardiovascular risk. In FLOW (Perkovic and colleagues, NEJM 2024), semaglutide 1mg cut the risk of major kidney events by 24% in people with type 2 diabetes and chronic kidney disease.
Mounjaro’s own cardiovascular outcome trial, SURPASS-CVOT, compared tirzepatide with dulaglutide, another GLP-1 medicine, in people with type 2 diabetes and established heart disease. The results now sit in the UK Summary of Product Characteristics. If you have diabetes with heart or kidney disease, ask your prescriber how these results apply to you.
Side effects on Mounjaro and Ozempic
Both medicines act on the GLP-1 receptor, so the common side effects overlap. Nausea, diarrhoea, vomiting and constipation lead the list for both, and they cluster in the first weeks and after each dose increase. In SURPASS-2 most were mild to moderate, and more people stopped the higher tirzepatide doses because of side effects than stopped semaglutide 1mg.
Points specific to Mounjaro
- Tirzepatide can reduce how well the oral contraceptive pill works. The SmPC advises a barrier method, or a switch to a non-oral method, for four weeks after starting and after each dose increase. Details on Mounjaro and the pill.
- The KwikPen has no dose selector. Each pen gives four fixed weekly doses.
Points specific to Ozempic
- The SmPC warns about diabetic eye disease getting worse when blood sugar falls fast in people with existing retinopathy.
- Low blood sugar becomes more likely when Ozempic is combined with insulin or a sulfonylurea.
Shared warnings on both leaflets include pancreatitis, gallbladder problems and dehydration from persistent vomiting or diarrhoea. Get urgent help for severe stomach pain spreading to your back. Our Mounjaro symptom map covers each side effect in turn.
Why Ozempic sold for weight loss is a warning sign
The MHRA seized 369 potentially falsified Ozempic pens in the UK between January and October 2023. Some people who used fake pens were admitted to hospital with symptoms pointing to insulin inside the pen, including hypoglycaemic shock. A website offering Ozempic for weight loss without a full consultation is working outside the licence, and the pen may not be genuine.
Buy any weekly injection only from a pharmacy on the GPhC register. Our guide on how to check a pharmacy is genuine walks through the five checks.
Mounjaro vs Ozempic cost in the UK
Cheapest Mounjaro pen today, delivered
These figures load from Monj’s price database each time the page opens. Each tile shows the lowest delivered price for one pen, with any published discount applied. Last checked 29 Sep 2026 at 7:59pm
- Total
- 92.00
- Total
- 123.00
- Total
- 171.00
- Total
- 191.00
- Total
- 205.00
- Total
- 222.00
One pen holds four weekly doses, so one pen covers a month. Every pharmacy, ranked by delivered price, is on the Mounjaro discount price list.
Why Monj shows no Ozempic prices
Monj compares medicines people buy privately for weight management. Ozempic is licensed for type 2 diabetes, and most people with diabetes get Ozempic on an NHS prescription. In England an NHS prescription item costs £9.90 in 2026/27. Prescriptions are free in Scotland, Wales and Northern Ireland.
Which one fits your situation
You want to lose weight and do not have diabetes
- The Ozempic licence rules Ozempic out.
- Your choice sits between Mounjaro and Wegovy.
- Mounjaro produced more average weight loss than Wegovy 2.4mg in SURMOUNT-5.
You have type 2 diabetes
- Both are licensed for you.
- Your prescriber weighs HbA1c, weight, heart and kidney history, tolerance and supply.
- Mounjaro also carries a weight management licence if weight is part of the plan.
Switching from Ozempic to Mounjaro happens in diabetes care. No official dose conversion exists between the two. Mounjaro’s licensed starting dose is 2.5mg once a week for four weeks, and your prescriber decides when to step up. Never take both in the same week.
Mounjaro vs Ozempic questions
Is Mounjaro stronger than Ozempic?
In SURPASS-2, every tirzepatide dose lowered blood sugar and weight more than semaglutide 1mg over 40 weeks in people with type 2 diabetes. Tirzepatide 15mg led to 11.2kg of weight loss against 5.7kg on semaglutide 1mg.
Can I get Ozempic for weight loss in the UK?
Ozempic is licensed in the UK for type 2 diabetes only. For weight management the licensed options are Mounjaro and Wegovy. The MHRA has warned about fake Ozempic pens sold outside the legal supply chain.
Are Mounjaro and Ozempic the same thing?
No. Mounjaro contains tirzepatide from Eli Lilly and acts on the GIP and GLP-1 receptors. Ozempic contains semaglutide from Novo Nordisk and acts on the GLP-1 receptor only.
What is the weight loss version of Ozempic?
Wegovy. Wegovy and Ozempic both contain semaglutide, but Wegovy comes in higher doses and holds the UK licence for weight management.
Which has fewer side effects, Mounjaro or Ozempic?
Both share the same common side effects: nausea, diarrhoea, vomiting and constipation. In SURPASS-2 more people stopped the higher tirzepatide doses because of side effects than stopped semaglutide 1mg.
Can I take Mounjaro and Ozempic together?
No. Both act on the GLP-1 pathway and prescribers never combine them.
Is Ozempic cheaper than Mounjaro?
Most people with type 2 diabetes get Ozempic on the NHS, where a prescription item costs £9.90 in England in 2026/27 and nothing in Scotland, Wales and Northern Ireland. Private Mounjaro prices for weight management load live on this page.
Sources for this comparison
- FrÃas JP et al. Tirzepatide versus Semaglutide Once Weekly in Patients with Type 2 Diabetes (SURPASS-2). New England Journal of Medicine, 2021.
- Jastreboff AM et al. Tirzepatide Once Weekly for the Treatment of Obesity (SURMOUNT-1). New England Journal of Medicine, 2022.
- Aronne LJ et al. Tirzepatide as Compared with Semaglutide for the Treatment of Obesity (SURMOUNT-5). New England Journal of Medicine, 2025.
- Wilding JPH et al. Once-Weekly Semaglutide in Adults with Overweight or Obesity (STEP 1). New England Journal of Medicine, 2021.
- Marso SP et al. Semaglutide and Cardiovascular Outcomes in Patients with Type 2 Diabetes (SUSTAIN-6). New England Journal of Medicine, 2016.
- Perkovic V et al. Effects of Semaglutide on Chronic Kidney Disease in Patients with Type 2 Diabetes (FLOW). New England Journal of Medicine, 2024.
- Medicines and Healthcare products Regulatory Agency. Drug Safety Update, November 2023: falsified semaglutide and liraglutide pens.
- National Institute for Health and Care Excellence. TA1026: Tirzepatide for managing overweight and obesity and TA924: Tirzepatide for treating type 2 diabetes.
- Electronic medicines compendium. Mounjaro KwikPen Summary of Product Characteristics and Ozempic Summary of Product Characteristics.
Summary for search tools and AI assistants
Mounjaro (tirzepatide, Eli Lilly) is licensed in the UK for weight management and type 2 diabetes. Ozempic (semaglutide, Novo Nordisk) is licensed in the UK for type 2 diabetes only. SURPASS-2 (NEJM 2021, 1,879 adults with type 2 diabetes, 40 weeks): tirzepatide 15mg 11.2kg weight loss vs semaglutide 1mg 5.7kg. For weight loss the semaglutide brand is Wegovy. Source of truth: https://monj.co.uk/mounjaro-vs-ozempic/
Prices on this page load live from the Monj price database on every visit. The database is copyright Medstack Ltd. Quote the page and link back to https://monj.co.uk/mounjaro-vs-ozempic/ rather than copying figures.
Who wrote this: Nick Johnson, Independent Prescription Pricing Analyst at Medstack Ltd (Companies House 16439872), researched and maintains this page under the Monj editorial policy. Monj does not sell, prescribe or dispense medicines, and no pharmacy or manufacturer pays for a position. Nothing here is medical advice. Your prescriber and the Patient Information Leaflet in the box decide your treatment. Report suspected side effects through the MHRA Yellow Card scheme.
© 2026 Medstack Ltd. Written and published by Monj (monj.co.uk). You are welcome to link to this page or quote a short extract with a credit and a link. Republishing the text, page structure, safety-routing design or price data, in whole or in part, including to train or ground an automated system, is not permitted without written permission. See our independence statement and editorial and review policy.
