Authored: 19/03/2023

Mounjaro (Tirzepatide) is an injectable medicine used to help adults manage their weight. It works by acting on hormones that control appetite, helping to reduce hunger and make you feel fuller.
You can buy Mounjaro weight loss pens from our UK registered online prescribing service. Mounjaro is the latest GLP-1 weight loss injection available in the UK, and is the most effective. It has surpassed the effectiveness of Semaglutide (Ozempic + Wegovy), with patients seeing as much as 22.5% body weight loss.
You can order Mounjaro after completing an online assessment with our GPs. If a prescription is approved, this is passed to our pharmacy team, who prepare and post your treatment.
Wegovy is from the same family of drugs, and is licensed for weight loss use in the UK. You can read our guide on how patients can switch from Wegovy to Mounjaro, if you are interested in switching treatment.
Price | From £139 / Month |
How it works | Suppresses appetite |
Effectiveness | 15-20% loss in the average patient |
Eligibility | BMI over 30, or over 27 with high blood pressure or cholesterol |
Side effects | Common side effects can include fatigue, dizziness, insomnia |
Dosage | Starting at 2.5mg ONCE weekly. Titrating up by 2.5mg each month. Maximum dosage of 15mg ONCE weekly. |
Mounjaro is a highly effective, UK licensed weight loss treatment. It has been shown in clinical trials to help achieve up to 23% body weight loss. It is the latest GLP-1 weight loss injection, and is used for people with a body mass index (BMI) over 30. It can also be prescribed for patients with a BMI of 27+ and a weight-related medical condition, such as high blood pressure or cholesterol.
It contains the drug tirzepatide and is a registered trademark of Eli Lilly.
It is known as Zepbound in the US, but launched in the UK under the brand name Mounjaro.
It is used ONCE weekly, as a subcutaneous (under the skin) injection. More information on how to inject Mounjaro can be found in the Patient Information Leaflet.
Mounjaro weight loss pens mimic the action of GLP-1, a natural hormone produced in the gut. This innovative treatment promotes significant weight loss for patients by acting similarly to GLP-1. It's two main effects are;
Both actions lead to eating fewer calories, which results in weight loss. Focusing on a reduced-calorie diet can amplify the benefits of Mounjaro.
Mounjaro also aids in preventing excess sugar from being converted into fat, reducing fat storage in the body.
A full account of how Mounjaro works can be found in our guide.
Mounjaro should only be used to help with weight loss if you have already tried and failed to lose weight through exercise and diet alone. Mounjaro is now available in the UK, however there are other GLP-1 drugs which are also available. These include Saxenda, Wegovy and Ozempic.
Mounjaro can be used for patients who have a BMI of over 30, or in patients with a BMI over 27, and other risk factors such as;
To read more about our UK patients experience with this treatment, you can read some of our patients Mounjaro reviews.
When using Mounjaro pens to suppress appetite, you can expect to lose around 15-25% of your initial body weight after completing treatment. This is the most effective of all the released GLP-1 medications so far.
These figures have been achieved by patients who have maintained on the highest strength of Mounjaro, which is the 15mg strength.
Patients who maintain at 10mg, lose on average of 21%, while patients who maintain at 15mg, can lose around 22.5%.
The lower strengths of Mounjaro 2.5 and 5mg will not achieve the best results. While some weight loss will be observed, the primary function of these doses is to help your body adjust to the drug without experiencing serious side effects.
The dosage table below outlines the recommended titration for Mounjaro when used for weight loss.
Weeks | Dose | Notes |
---|---|---|
1-4 | 2.5 mg once weekly | Initial dose for titration |
5-8 | 5 mg once weekly | Assess tolerance before increase |
9-12 | 7.5 mg once weekly | Assess tolerance before increase |
13-16 | 10 mg once weekly | Monitor for efficacy and tolerability |
17-20 | 12.5 mg once weekly | Further increase based on clinical response |
21 onwards | 15 mg once weekly | Maintenance dose if well tolerated |
While increasing the dose, if you find the side effects problematic for two weeks or more, you should discuss this with your doctor or pharmacist. You can read more in our Mounjaro dosage guide.
The cost of Mounjaro in the UK starts from £139 / month. If titrating all the way up to the maximum dose and maintaining, the annual cost is £1,434.65. See our pricing table below or a full breakdown of Mounjaro prices.
Dosage | Price |
---|---|
1 Pen - 4 x 2.5mg doses | £139 |
1 Pen - 4 x 5mg doses | £139 |
1 Pen - 4 x 7.5mg doses | £169.99 |
1 Pen - 4 x 10mg doses | £189.99 |
1 Pen - 4 x 12.5mg doses | £204.95 |
1 Pen - 4 x 15mg doses | £204.95 |
NOTE: One pen contains four doses, so a pen lasts for 4 weeks.
The most common side effects with Mounjaro affect the digestive system. These can include things like nausea, vomiting, diarrhoea and constipation. Most patients should see these effects subside after a few days.
Other common side effects include:
The dosage titration of the drug, is designed to minimise side effects. Starting with Mounjaro 2.5mg, and moving up through 5mg in 2.5mg increments, helps the body adjust to the drug's impact. Doing this gradual titration, will allow you to minimise side effects and get the most out of your treatment.
You can read a full account of Mounjaro side effects in our advice pages.
The preferred and safest method of losing weight is via a healthy diet and increased physical exercise.
The NHS offers a 12-week weight loss plan for patients. Further information from the NHS is available for exercise and diets. Is it expected that Mounjaro will be available on the NHS, for certain patients, however this has yet to be confirmed.
Other GLP-1 drugs available in the UK as an alternative to Mounjaro include
For many individuals, injectable treatments may not be a preferred option. There are more traditional weight loss pills available from our weight loss service, such as Orlistat. This contains 120mg of the drug, and works by preventing 1/3rd of the fat from the food you eat from being absorbed.
You can also compare Ozempic and Mounjaro, as well as understand the differences between Wegovy and Mounjaro, by reading our helpful advice guides.
Medication | Price | % Average Weight Loss |
---|---|---|
Ozempic | From £139 per month | Up to 15% |
Mounjaro (Tirzepatide) | From £139 per month | Up to 22% |
Wegovy (Semaglutide) | From £139 per month | Up to 16% |
Saxenda (Liraglutide) | From £75.00 per pen | Up to 10% |
All of our medication and condition content is written by UK qualified pharmacists and doctors.
Authored: 19/03/2023
Reviewed: 20/03/2025
Saxenda | Xenical | Orlistat | Mysimba | |
Ingredient | Liraglutide | Orlistat 120mg | Orlistat 120mg | Naltrexone/Bupropion |
Mechanism | Regulates appetite | Reduces fat absorption | Reduces fat absorption | Regulates appetite |
Dose | Injected once daily | One three times daily with meals | One three times daily with meals | Gradually increased to 4 tablets daily |
Some medicines can interact with Mounjaro such as:
Mounjaro can be dangerous in certain conditions so it is especially important to mention if you have: