Ozempic vs Mounjaro: What’s the Difference?

Ozempic and Mounjaro are medications that can trigger weight loss. However, people often mistake the two. These medicines have different uses and are therefore ideal for different people depending on individual goals.

In the UK, doctors prescribe Ozempic primarily for Type 2 Diabetes, while Mounjaro is for weight management in eligible adults that can also help with diabetes. Choosing between these two medications often comes down to your needs and the prescriber's recommendations.

This guide explains how Mounjaro and Ozempic compare and what to consider when choosing between them. We'll also highlight Curely's safe and legal weight loss medication services for UK patients.

Ozempic vs Mounjaro at a Glance

What Is Ozempic?

Ozempic is a prescription medication that contains the active ingredient semaglutide. It mimics a natural hormone called GLP-1 (glucagon-like peptide-1), which helps your body release insulin when blood sugar is high.

Patients take Ozempic as a once-a-week subcutaneous injection, meaning you inject it under the skin starting with the lowest amount of 0.25 mg, with dose increases according to your healthcare practitioner's guidance.

Doctors prescribe Ozempic to improve blood sugar control in adults with type 2 diabetes, but it can also reduce the risk of major cardiovascular events such as strokes or heart attacks. Semaglutide can decrease your appetite and slow down how quickly food leaves your stomach, which can make you feel fuller.

Ozempic Eligibility Requirements in the UK

You must have an official diagnosis of Type 2 diabetes to legally take Ozempic.

The National Health Service (NHS) will not prescribe it as a first-line treatment. Your GP will only prescribe Ozempic if your blood sugar levels (HbA1c) are still too high even though you're already taking metformin or other standard first-line diabetes tablets.

A doctor may also prescribe it if you can't take standard treatments because they cause severe side effects or are medically unsuitable for you.

Because Ozempic can cause weight loss, the National Institute for Health and Care Excellence (NICE) guidelines state a patient with Type 2 diabetes must also meet the following weight criteria:

• A body mass index (BMI) of 35 or above, plus a medical or psychological condition related to obesity.
• A BMI below 35 if putting you on insulin would severely impact your job, or your weight affects other health issues that would improve if you lost weight.

Who Can't Use Ozempic?

• Personal or Family History of Medullary Thyroid Cancer (MTC): Animal studies showed a link between semaglutide and thyroid tumors.
• Multiple Endocrine Neoplasia Syndrome Type 2 (MEN 2): A rare genetic condition that causes tumors in the endocrine glands.
• Pregnancy or Breastfeeding: According to a study on pregnancy outcomes after semaglutide exposure, Ozempic can cause fetal harm. Guidelines state that you must stop taking the medication at least two months before trying to get pregnant.
• Severe Allergic Reactions: People who have an anaphylactic reaction to semaglutide or any ingredients in the injection shouldn't take it.

Can Ozempic Treat Weight Loss?

Because of its effects on digestion, semaglutide injections can cause weight reduction. However, the UK doesn't license Ozempic for weight loss. Similarly, the FDA hasn't approved it for weight loss in the US, so using Ozempic for this purpose would be considered off-label.

What Is Mounjaro?

Mounjaro is a prescription weight loss injection that contains the active ingredient tirzepatide. This medication affects two hormone pathways: GLP-1 and glucose-dependent insulinotropic polypeptide (GIP), making it popular among obese adults who want to manage their weight.

Mounjaro can also:

• Reverse Type 2 Diabetes: It makes the pancreas release insulin only when blood sugar is high and reduces the amount of sugar the liver makes.
• Relieve Sleep Apnoea: Tirzepatide can treat moderate-to-severe Obstructive Sleep Apnoea (OSA) in patients with obesity.
• Protect the Heart and Kidneys: According to the landmark SURPASS-CVOT study, published in the New England Journal of Medicine, tirzepatide can reduce the risk of major cardiac events (such as heart attacks and strokes) and help protect kidney function over time.
• Clear Fatty Liver Disease: Tirzepatide can reduce liver fat, thereby improving inflammation and scarring.

Mounjaro's dosing schedule is once weekly, as a subcutaneous injection, starting with the lowest strength of 2.5mg. Your prescriber should tell you the best time to increase your Mounjaro dose, but it's usually after at least four weeks on the same amount.

Mounjaro Eligibility Requirements in the UK

Eligibility for Mounjaro in the UK depends on whether you're trying to access it for a lower price through the NHS or if you are paying for it privately.

NHS Eligibility

You must have a BMI of 35 or above, or 40 or above if you get it directly from a participating GP. Patients must also have weight-related health conditions such as type 2 diabetes or high blood pressure.

All patients must agree to use the medication with an official NHS-approved lifestyle and reduced-calorie diet program.

Private Eligibility

The private eligibility requirements are:

• A BMI of 30 or above
• A BMI of 27 to 29.9 with one health condition such as high blood pressure and high cholesterol.

Who Is NOT Eligible for Mounjaro?

Mounjaro is not suitable for the following people:

• Under 18 or over 75-85 (depending on the provider).
• Pregnant or breastfeeding.
• Have a personal or family history of medullary thyroid cancer or MEN 2.
• Have a history of pancreatitis.
• Have severe kidney disease or active gastrointestinal disease.

Mounjaro vs Ozempic: Which Is Better for You?

Choose Ozempic if:

Ozempic may be the right option if your main goal is blood sugar control as part of a diabetes treatment plan. It can help you manage your blood glucose levels. Also, choose Ozempic if your healthcare professional believes it's the most suitable medication based on your medical history.

A doctor's treatment plan should consider factors such as low blood sugar, cardiovascular risk, and any prior side effects before deciding your appropriate maintenance dose and schedule for Ozempic.

Choose Mounjaro if:

Mounjaro may be more suitable if your goal is to lose weight with a licensed treatment. Its active ingredient, tirzepatide, has a dual action that helps lower food intake and improve blood sugar control. This leads to significant weight loss.

According to the landmark SURMOUNT clinical trials, users lost about 20.9% of their total body weight on Mounjaro's maximum dose of 15mg. However, note that real world results depend on factors such as your starting weight, lifestyle, dose, and how well you tolerate treatment.

Mounjaro & Ozempic Side Effects

Common Side Effects

• Nausea (slightly more intense for Ozempic)
• Vomiting
• Diarrhoea (slightly more for Mounjaro)
• Stomach discomfort
• Reduced appetite
• Constipation (slightly more intense for Mounjaro)

Side effects can be more noticeable when starting the treatment or moving up the dosage schedule. It's why your doctor usually increases the amount gradually.

Serious But Less Common Side Effects

While it's not as common, some people may experience adverse side effects that require urgent medical attention. These include:

• Acute Pancreatitis: Causes severe, persistent abdominal pain that spreads through to your back with non-stop vomiting.
• Gallbladder Problems: Usually feels like a sudden, sharp pain in the upper right side of the stomach, sometimes accompanied by a fever or yellowing of the skin/eyes (jaundice).
• Dehydration & Low Blood Pressure: Severe dehydration reduces blood volume, leading to low blood pressure (hypotension), dizziness, fainting, and even acute kidney injury.
• Allergic Reactions: A severe reaction can cause swelling of the face, lips, tongue, or throat, leading to dangerous breathing difficulties.
• Low Blood Sugar: Taking Ozempic or Mounjaro alongside other diabetes medications such as insulin or sulfonylureas can increase the risk of Hypoglycaemia.

Ozempic vs Mounjaro UK Cost

Both medicines are prescription-only, but they come at different prices. Private prescription costs vary among providers, depending on the prescribed dose and whether ongoing clinical support is part of the fee.

The average cost of a Mounjaro 4-dose KwikPen is £130 to £170 per month (for the starting dose). Higher Mounjaro doses are usually more expensive.

Ozempic costs £139 to £180 per month, and the price stays relatively flat even as you move up to the higher doses.

Note that while they're both weekly injections, Mounjaro and Ozempic have different uses in the UK, so cost should not be the deciding factor.

If your goal is targeted weight loss, we recommend Mounjaro or another licensed treatment, such as Wegovy. Never compare Mounjaro to Ozempic as weight loss drugs.

Wegovy vs Ozempic and Mounjaro

Wegovy vs Ozempic

Ozempic is not for weight loss. People who want to use semaglutide as part of their weight loss journey should get a prescription for Wegovy. It's a weight-loss injection that also contains semaglutide but is licensed in the UK for weight-loss treatment in eligible adults. There's even a Wegovy pill.

Why the Difference?

Novo Nordisk makes both Ozempic and Wegovy, plus they contain the same active ingredient. However, they went through different clinical studies and have different approved dosages, which is why Wegovy is for weight loss while Ozempic is for diabetes treatment. Curely only prescribes approved weight loss treatments in the UK for eligible adults.

Wegovy vs Mounjaro

Wegovy acts on GLP-1, while Mounjaro acts on GLP-1 and GIP. Both are injections that you take once weekly to support weight loss alongside diet and physical activity.

According to the STEP UP clinical trials, Wegovy 7.2 mg (the highest dose) resulted in an average weight loss of 20.7%, about the same as Mounjaro. With these results, the choice between Mounjaro and Wegovy depends on preferences, eligibility, general health, and side effects.

Choose Curely for Licensed Weight Loss Treatments

At Curely, you'll receive expert clinical support and safe weight loss medications, such as Mounjaro and Wegovy.

Our prescribing team will recommend the most suitable treatment for you after you complete a thorough online consultation. If you're eligible, we'll prescribe and deliver the treatment discreetly to your home or workplace: no in-person GP appointments or pharmacy visits.

With flexible subscriptions and the option to pause or adjust your treatment as needed, Curely makes it easier to meet your weight loss goals. Start your journey today.

FAQs

Is Mounjaro Better Than Ozempic?

Mounjaro is the better choice for weight management in eligible adults. Avoid taking Ozempic for this purpose, as it's considered off-label use.

Is Ozempic Available for Weight Loss in the UK?

No. Ozempic for weight loss is off label in the UK. However, patients who want to use semaglutide for this purpose can speak to Curely about Wegovy. It's an approved treatment for obesity in the UK that can lead to benefits such as weight loss, relieving sleep apnoea, blood sugar control, and reducing the risk of cardiovascular disease.

Is Mounjaro Stronger Than Ozempic?

According to the SURPASS-2 trial, Mounjaro was more effective at lowering HbA1c (average blood sugar levels) and reducing body weight than Ozempic. Mounjaro is also the medication that's licensed for weight loss in the UK.

Can You Switch From Ozempic to Mounjaro?

Yes, but only with prescriber guidance. People usually make the switch because their blood sugar control is less effective with Ozempic. Always speak to a clinician for guidance and safety before switching, as these medications have different active ingredients and may cause side effects during the transition.

Can You Buy Mounjaro Online Safely?

Yes, but only through a regulated UK provider. With Curely, you can safely access Mounjaro and Wegovy after an online consultation that reviews your medical history and overall health. We also offer weight loss pills.

Final Thoughts

The main difference between Ozempic and Mounjaro is that Ozempic is a type 2 diabetes medicine, while Mounjaro is licensed for weight management in eligible adults in the UK. For this reason, avoid using Ozempic as a weight loss medication, as it's considered off-label.

Curely can help you find the best weight loss treatment for your needs. We thoroughly verify eligibility for your safety and obtain medications from reputable sources.

Reference List

• Allen, Annabel Kartal. “Novo Nordisk’s High-Dose Wegovy Touts near 28% Weight Loss in Early Responders.” Clinical Trials Arena, 13 May 2026.
• Feier, Catalin Vladut Ionut, et al. “Assessment of Thyroid Carcinogenic Risk and Safety Profile of GLP1-RA Semaglutide (Ozempic) Therapy for Diabetes Mellitus and Obesity: A Systematic Literature Review.” International Journal of Molecular Sciences, vol. 25, no. 8, 1 Jan. 2024.
• Jastreboff, Ania M., et al. “Tirzepatide Once Weekly for the Treatment of Obesity.” New England Journal of Medicine, vol. 387, no. 3, 4 June 2022, pp. 205–216.
• “Lilly’s SURPASS-2 Results Published in the New England Journal of Medicine Show Tirzepatide Achieved Superior A1C and Body Weight Reductions Compared to Injectable Semaglutide in Adults with Type 2 Diabetes | Eli Lilly and Company.” Investor.lilly.com, 24 June 2021.
• Line Kolding, et al. “Pregnancy Outcomes after Semaglutide Exposure.” Basic & Clinical Pharmacology & Toxicology, vol. 136, no. 4, 13 Mar. 2025.
• Nicholls, Stephen J., et al. “Cardiovascular Outcomes with Tirzepatide versus Dulaglutide in Type 2 Diabetes.” New England Journal of Medicine, vol. 393, no. 24, 18 Dec. 2025, pp. 2409–2420.