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 an average of 23% 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.
Summary
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.
What is Mounjaro?
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 Wegovy 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;
It helps regulate appetite, making it easier to eat less
It makes you feel fuller for longer
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.
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;
Diabetes type 2
High cholesterol
Obstructive sleep apnoea
High blood pressure
To read more about our UK patients experience with this treatment, you can read some of our patients Mounjaro reviews.
How Effective Is it?
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.
Dosage
The dosage table below, outlines the recommended titration for Mounjaro when used for weight loss.
Mounjaro Dose Titration Schedule
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.
UK Pricing
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.
Mounjaro Pen Dosages and Prices
Dosage
Price
1 Pen 2.5mg
£139
1 Pen 5mg
£139
1 Pen 7.5mg
£169.99
1 Pen 10mg
£189.99
1 Pen 12.5mg
£204.95
1 Pen 15mg
£204.95
NOTE: One pen contains four doses, so a pen lasts for 4 weeks.
Alternatives
The preferred and safest method of losing weight is via a healthy diet and increased physical exercise.
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.
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:
Feeling weak or tired
Dizziness
Insomnia
Injection site reactions such as bruising, pain or a rash
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.
Drinking alcohol isn’t strictly prohibited while taking Mounjaro, but it can increase the risk of side effects like nausea or low blood sugar. It’s best to limit your alcohol intake and talk to your doctor for advice tailored to your situation.
How long can Mounjaro be out of the fridge?
Mounjaro can be kept unrefrigerated for up to 30 days, as long as the temperature doesn’t go above 30°C. Make sure to keep it in its original packaging to protect it from light.
Can I get Mounjaro on the NHS?
Yes, Mounjaro is available on the NHS, but it’s usually prescribed as part of a specialist weight loss program for patients who meet specific criteria. It may also be prescribed for managing type 2 diabetes. Speak to your GP for more details, as availability can vary.
Can I use Mounjaro if I’m on the contraceptive pill?
Yes, you can, but Mounjaro may affect how well oral contraceptives work. If you experience vomiting or diarrhea, it’s especially important to use an additional form of contraception, like condoms, or switch to a non-oral contraceptive for at least 4 weeks after starting Mounjaro or increasing your dose.
How should I store Mounjaro?
Mounjaro should be stored in the refrigerator at a temperature between 2°C and 8°C. If necessary, you can keep it outside the fridge for up to 30 days, as long as the temperature stays below 30°C. After 30 days out of the fridge, you’ll need to throw it away.
Why am I not losing weight on Mounjaro?
Weight loss can take time, and there are a few reasons why you might not be seeing results yet:
You may not have reached the highest dose of Mounjaro.
You might not be following a calorie-reduced diet or exercise plan.
You could have hit a weight loss plateau.
Healthy weight loss is typically around 0.5–1 kg (1–2 lbs) per week. If you’ve been on Mounjaro for several months without any progress, it’s a good idea to talk to your doctor.
What should I do if I miss a dose of Mounjaro?
If you miss a dose of Mounjaro, take it as soon as you remember, as long as it’s within 4 days of the missed dose.
Written by Qualified Experts
All of our medication and condition content is written by UK qualified pharmacists and doctors.
Some medicines can interact with Mounjaro such as:
Anticoagulants (blood thinning medication) such as warfarin
Anti-diabetic medication such as sulfonylureas and insulin
GLP-1 receptor agonists such as Victoza
Other conditions and Mounjaro
Mounjaro can be dangerous in certain conditions so it is especially important to mention if you have:
Heart failure
Aged 75 years or older
Severe renal (kidney) disease
Severe hepatic (liver) disease
Pancreatitis
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