Authored on 17 April 2026 by Dr Ruch Karunadasa,
Medically reviewed 29 April 2026 by Mr Adeel Arshad.
Next review due: 29 April 2027
Mounjaro
Mounjaro (Tirzepatide) - effective weight loss medication.
Targeting both GLP-1 and GIP receptors to help curb your appetite, make you feel fuller and improve the body's usage of fat stores.
Part of our weight loss treatment planThis page provides factual information about Mounjaro (Tirzepatide) for educational purposes. This is not an advertisement. A prescription will only be issued following a successful clinical assessment by our healthcare team.
Mounjaro for weight loss
What is the science behind Mounjaro?
Mounjaro employs a multifaceted approach to enhance weight management. It facilitates the release of insulin in response to elevated blood sugar levels, aids in the removal of excess sugar from the bloodstream, curtails the liver's production and release of excessive sugar, reduces overall food intake, and moderates the speed at which food exits the stomach. Notably, the latter effect gradually diminishes over time.
How does Mounjaro work?
CHIEF MEDICAL OFFICER
Dr Ruchira Karunadasa
MB BS - GP
Mounjaro promotes weight loss by decreasing appetite, as well as directly impacting the pathways that lead to fat loss. Unlike other GLP-1 medications, Mounjaro activates both GLP-1 and GIP receptors, promoting the utilisation of stored fat for energy in addition to curbing appetite.
Decrease food intake
Enhances insulin secretion
Improves insulin sensitivity
Additional actions include delayed gastric emptying* and reduced glucagon levels
*This effect diminishes over time.
Is Mounjaro suitable for me?
When you join PrivateDoc we will assess your individual circumstances to see if we think Mounjaro will help with your weight management.
Mounjaro (pronounced mown-JAHR-OH; tirzepatide) is licensed in the UK as an adjunct to a reduced-calorie diet and increased physical activity for weight management in adults with obesity, or overweight with at least one weight-related comorbidity. PrivateDoc will evaluate your medical history, current health status, and other factors such as medicines you may be taking, to determine if Mounjaro is suitable for you.
How do I use Mounjaro?
Take Mounjaro once a week, selecting a day that suits your schedule. Administer Mounjaro at any time on your chosen day. However, if you wish to change your dosing day, ensure a minimum of 3 days (72 hours) between doses. If a dose is missed, take it within 4 days (96 hours) after the missed dose. If more than 4 days have elapsed, skip the missed dose and resume on your regular day. Avoid taking two doses within 3 days of each other. Consider setting a reminder on your phone for your Mounjaro day, and if you change the day, update your reminder accordingly.
What are the dose options for Mounjaro
The starting dose of Mounjaro is 2.5mg once a week for 4 weeks. After 4 weeks your doctor will increase your dose to 5mg once a week. Let your doctor know how you’re doing on the 2.5mg and 5mg doses during your checkup. Your doctor will decide if additional dose increases are needed. Do not change your dose unless your doctor has told you to. The dose options available for Mounjaro are 2.5mg, 5mg, 7.5mg, 10mg, 12.5mg and 15mg. You can stop increasing when you reach a dose you feel is working for you. For Mounjaro, 5mg, 10mg and 15mg are considered maintenance doses.
How do I administer my Mounjaro injection?
Administer Mounjaro by subcutaneous injection, either in your stomach (abdomen), thigh, or upper arm, once a week at any time of the day. Change your injection site each week. You may use the same area of your body, but be sure to choose a different injection site in that area. Always use a new pen needle for each injection to help prevent infections and blocked needles. In case of an overdose, promptly contact your healthcare provider or seek medical advice.
How much does Mounjaro cost?
The monthly cost of Mounjaro starts from £167 and the price increases each month with the increased dose.
Mounjaro Weight Loss results.
In recent studies (SURMOUNT 1), individuals taking Mounjaro experienced significant weight loss compared with the placebo group.
At 72 weeks the average weight loss was 13.8kg on the 5-mg dose, 19.8kg on the 10-mg dose, and 21.2kg on the 15-mg dose. This equated to an average baseline reduction of 16.0% on the 5mg-dose, 21.4% on the 10mg-dose and 22.5% on the 15mg-dose.
What are the possible side effects of taking Mounjaro?
As is the case with any medication, Mounjaro can cause some patients to experience side effects. Some of these are listed below but for the full list please click here for a copy of the patient information leaflet
Very common and common side effects:
- Nausea and/or vomiting
- Gastrointestinal side effects – e.g. diarrhoea, constipation, bloating, indigestion, burping, gas, reflux (heartburn)
- Symptoms of low blood sugar levels (hypoglycaemia) – these can include but are not limited to sweating, dizziness, feeling light headed, headache, feeling drowsy, feeling weak, confusion, mood changes such as feeling irritable
- Allergic reactions (hypersensitivity) – e.g. rash, itching, eczema
- Abdominal pain
- Hair loss
- Tiredness
- Fast pulse
- Injection site reactions – e.g. itching, redness, swelling
- Increased levels of pancreatic enzymes – e.g. lipase and amylase
Uncommon side effects:
- Gallstones
- Gallbladder infection
- Injection site pain
- Increased blood levels of calcitonin
Serious side effects:
- Inflammed pancreas (acute pancreatitis)
- Severe allergic reactions (Anaphylaxis)
How do I store Mounjaro?
Unused pens:
Store unused pens in the refrigerator between 2°C to 8°C
Unused pens may be used until the expiration date printed on the label if the pen has been kept in the refrigerator
Do not freeze.
Used pens:
You may store your pen at room temperature up to 30°C, or in the refrigerator, after you inject the first dose. All pens following first use must be discarded after 30 days.
Keep away from heat.
What if im going on a holiday?
Mounjaro remains viable unrefrigerated for a duration of up to 30 days, provided the temperature does not exceed 86°F (30°C). To safeguard the pen from light exposure, keep it in its original carton.
Keep the container out of the reach of children. Do not recycle your sharps container, follow your community guidelines for the right way to dispose of your sharps disposal container.
How do I dispose of your my Mounjaro pens
Dispose of the pen 30 days after first use or after receiving 4 weekly doses, even if it looks like there may be some liquid left in the device. To dispose of safely, place the pen needles in an approved sharps disposal container immediately after use. If you lack an approved sharps container, use a sturdy household container made of heavy-duty plastic with a puncture-resistant lid. Ensure it is upright, stable, leak-resistant, and appropriately labelled to indicate hazardous waste.
Keep the container out of children's reach, and refrain from recycling the sharps container. Instead, adhere to community guidelines for the proper disposal of sharps containers. The pen device can be disposed of via normal household waste or by returning to your nearest pharmacy if there is still medication inside.
What diet should I follow on Mounjaro?
Whilst taking Mounjaro we recommend following a calorie-controlled diet to support your goals. As this can be a confusing area with lots of mixed messaging, we partnered with leading nutritionist Glen Matten to bring to you our very own PrivateDoc diet guide. You can find out more here: PrivateDoc Diet Guide
Where to buy Mounjaro online?
While many online retailers claim to supply genuine medicines, they may be unregulated, provided without a genuine doctor consultation and potentially very dangerous. You can rest assured, PrivateDoc is a fully registered digital health service. We have UK registered doctors that review and assess every consultation. All the medicines we supply are 100% genuine and fully regulated by the Medicines and Healthcare products Regulatory Agency (MHRA).
How the PrivateDoc
Weight Loss Programme works
* Your eligibility for our treatment plan will be assessed by a clinical professional following a consultation.
The Experts
Your health is in safe hands! Our clinical team are with you every step of the way.
Mounjaro vs Wegovy, Mysimba & Saxenda
Mounjaro employs a multifaceted approach to enhance weight management. It facilitates the release of insulin in response to elevated blood sugar levels, aids in the removal of excess sugar from the bloodstream, curtails the liver's production and release of excessive sugar, reduces overall food intake, and moderates the speed at which food exits the stomach. Notably, the latter effect gradually diminishes over time. Read more on the differences of medications here
FAQs
Discover answers to common questions about Mounjaro (tirzepatide).
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Where can I find the full list of Mounjaro side effects?
Like any prescription medicine, Mounjaro can cause side effects. The main examples are summarised in the What are the possible side effects of taking Mounjaro? section on this page.
For the full list, read the patient information leaflet before you start treatment. If a side effect worries you or does not go away, speak to your prescriber.
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Can I switch from Mounjaro to Wegovy?
Yes, switching from Mounjaro to Wegovy may be possible, but this will be assessed on a case-by-case basis by your prescribing clinician. Before making the decision to switch, it’s important to consider the following:
- Washout period required – You’ll need to wait at least 7 days after your last Mounjaro dose.
- Starting dose – If you’ve had no side effects and your gap between doses is less than 3 weeks, you may be eligible to start:
- Your weight loss goals – Depending on how much weight you are aiming to lose; it may be more beneficial to continue with Mounjaro rather than switch.
If you’ve experienced side effects, a longer washout period or lower starting dose may be required.
Please note: The final decision will always be made by our clinical team based on your consultation responses. Requesting a specific dose does not guarantee it will be prescribed
Benefits of Wegovy
- Works by targeting GLP-1 receptors, similar to Mounjaro.
- Clinical trials have shown an average weight loss of 16%, with many patients achieving more.
- Licensed for weight maintenance, meaning it is safe to continue even after you reach your goal weight.
- Long-term studies show patients can maintain their weight loss when staying on treatment.
- Proven cardiovascular benefits, including a significant reduction in the risk of heart attack or stroke.
Switching to Wegovy may be right for some patients and not for others. If you are considering a switch, speak to your prescribing clinician so you can decide together what is in your best interest.
Clinical authorship and medical review
The expert team leading our online clinics 2025
PrivateDoc is happy to introduce you to some of our leading UK licensed clinicians who will be supporting you through your weight loss journey
Dr Ruchira Karunadasa
Chief Medical Director
Adeel Arshad
Lead Clinician
