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- Mounjaro Weight Loss Injection
Patients taking this medication for the first time should start on the lowest dose to allow their body adjust to it safely
What is Mounjaro?
Mounjaro is a clinically proven weight loss aid prescribed to help with weight loss when other efforts have been ineffective.
Silence food noise
Targets the reward centre in your brain, so you’ll feel more satisfied after each meal and less likely to experience food focused thoughts.
Feel fuller for longer
Slows down the rate at which your stomach empties, helping to reduce your overall appetite.
Reduce cravings
Keeps your blood sugar level stable after eating, preventing spikes that can lead to increased hunger and cravings.
Overview
What is Mounjaro and How Does it Work?
Mounjaro is a treatment for weight loss. It is available as a prefilled pen that you inject yourself once a week. Mounjaro is the UK-licensed version of Zepbound, which is licensed in the US.
The active ingredient in Mounjaro is Tirzepatide. Tirzepatide attaches to receptors of hormones called GIP and GLP-1. GLP-1 and GIP are produced naturally in the body when you eat something.
Once tirzepatide is attached to the receptors, it mimics the same way GIP and GLP-1 work and tells the body to increase the amount of insulin from the pancreas. This helps the body regulate (control) blood sugar levels and reduce the amount of food you eat. It also helps:
- The body releases insulin (hormone) when blood sugar levels are high
- Stop the liver from making and releasing too much sugar
- The body removes excess sugar (glucose) from the blood
- Reduce how much food you eat
- Slow down how fast food leaves the stomach
How Effective is Mounjaro?
When using Mounjaro kwikpens to suppress appetite, you can expect to lose around 15-20% of your initial body weight after completing treatment with a balanced diet and exercise. This is the most effective of all the released GLP-1 medications so far including Wegovy.
These figures have been achieved by patients who have maintained on the highest strength of Mounjaro, which is the 15mg strength.
In a trial carried out by Eli Lilly, it was shown that patients who maintained dose at 10mg lost an average of 17% of their body weight whilst patients who maintained dose at 5mg, lost around 15%.
Where Can You Buy Mounjaro in the UK?
You can only buy Mounjaro in the UK with a prescription from a doctor at a registered pharmacy.
Alternatively, you can purchase Mounjaro online from Online Mens Clinic after completing a quick health consultation. Once you have been approved for treatment after a free consultation with a registered pharmacist, your medicine will be securely and discretely delivered to your UK address as soon as the next working day.
Mounjaro Weight Loss Alternatives
During your online consultation with a Online Mens Clinic pharmacist, the following alternatives to Mounjaro may be suggested:
Weight Loss Injections
- Saxenda: Saxenda is an injectable weight loss aid that contains the active ingredient Liraglutide, which is a GLP-1 receptor agonist.
- Wegovy: Wegovy is a once-weekly injectable weight loss aid that has the active ingredient Semaglutide. It is an appetite suppressant (GLP-1 receptor agonist).
Weight Loss Pills & Capsules
- Orlistat 120mg: Orlistat tablets are effective weight-loss tablets used to treat obesity. They are the generic version of Xencal and work by reducing the amount of fat the body absorbs.
- Mysimba: This medication is a combination of Naltrexone and Bupropion and is used to treat obesity.
- Xenical 120mg: The brand name version of Orlistat. These tablets contain the active ingredient orlistat and break down dietary fats into smaller pieces before your body absorbs them.
The Science Behind Mounjaro
Mounjaro has been approved for use by the FDA (American regulatory authority) and the UK MHRA and has been proven to be safe and effective for treating weight loss in obese patients and patients with type 2 diabetes.
Data has shown that patients can experience weight loss in as little as 4 weeks. Further weight loss can be observed until the study ends at 40 weeks. Patients at an optimal dose experienced a total weight loss of ~ 20% of their starting weight after 40 weeks.
Informational Sources
If you’d like to find out more about Mounjaro or weight loss medication in general, we’ve compiled a list of additional resources below for you to take a look at:
Mounjaro Reviews
Mounjaro has very positive reviews for those using it for weight loss (obesity/overweight treatment). Reviewers commented that in conjunction with regular exercise and improved eating habits, they were able to lose a large amount of weight and come off medications that they were prescribed for conditions caused by their weight.
Reviewers mentioned that they experienced minimal to no side effects when taking Mounjaro.
Directions of Use
Mounjaro Weight Loss Pen Dosage & Directions of Use
How to Use a Mounjaro KwikPen
Mounjaro comes in a pre-filled pen that is designed to deliver the medication under your skin (subcutaneously). The pen comes with a complete guide on how to use it. It is important to read and understand it before using the pen. To take your weekly dose of Mounjaro, follow these steps:
- Remove the KwikPen from the packaging, and check the expiration date
- Next, make sure that the site of the skin on your stomach, upper arm, or thigh is clean and dry
- Remove the cap from the pen and wipe the injection site with an alcohol swab
- Choose a new needle. This helps prevent infections and any blocked needles
- Push the capped needle straight into the pen and twist it until it is tight
- Pull off the outer needle shield (cap) and keep it. You will reuse it later
- Hold the pen with firm pressure against the skin at a 90-degree angle. Then press the button to retract the needle
- Once the needle is inserted into your skin, hold the pen still for 5 seconds, then release the button to retract (remove) the needle
- Throw away the used pen, and put the needle in a sharps container or follow your doctor's instructions for safe disposal
Mounjaro needs to be taken weekly. It is important to take it at the same time every week. Avoid injecting the medication into the same spot (site) every time to prevent skin irritation.
Need a step-by-step visual? See our guide: How to use a Mounjaro KwikPen.
Wondering about leftover liquid? Read our guide that covers what to do with the leftover liquid in the Mounjaro pen.
Dosage Schedule
Multiple doses of Mounjaro are available, as treatment typically begins at a low dose and slowly increases over a few months. This process is called dose titration. How your doses increase depends on how your weight loss journey is progressing and how well you are tolerating the treatment.
The starting dose for all new patients is 2.5mg of Mounjaro.
Typical Schedule (may vary based on your prescriber's advice)
Your prescriber will decide how and when to increase the dose based on your progress and any side effects.
Read our guide for more information about Mounjaro dosages.
Ingredients
Mounjaro Ingredients
The active ingredient:
- Tirzepatide
Other ingreients:
- Sodium phosphate dibasic heptahydrate, water for injections, Benzyl alcohol, phenol, glycerol, sodium chloride, concentrated hydrochloric acid, and sodium hydroxide (for pH adjustment)
Check the PIL for the complete ingredient list and speak to a pharmacist if you have any allergies.
Read our guide to find out more about how to store Mounjaro, including whilst travelling.
Side Effects
Mounjaro Side Effects
Like all medicines, Mounjaro can cause side effects, although not everyone will get them.
Common Side Effects of Mounjaro Weight Loss Pen
Common side effects of Mounjaro may affect up to 1 in 10 people. They include:
- Low blood sugar
- Flatulence (gas)
- Allergic reaction
- Dizziness
- Decreased appetite (feeling less hungry)
- Feeling tired
- Fast pulse (common in diabetes type 2 patients and not weight loss patients)
- Increases levels of pancreatic enzymes (uncommon in weight loss patients)
- Burping
- Indigestion
- Stomach pain
- Reflux or heartburn
- Hair loss in patients being treated for weight loss
Talk to your doctor or pharmacist about persistent, common side effects. Depending on where you are in your weight loss journey, your dose strength may need to be decreased.
Less Common Side Effects of Mounjaro Weight Loss Pen
Uncommon side effects may affect up to 1 in 100 people, they include:
- Increased Calcitonin levels in the blood
- Gallstones
- Low blood sugar levels
- Injection site pain
- Cholecystitis (infection of the gallbladder)
- Kidney problems and kidney failure
- Depression
Seek immediate medical help if you experience nausea and vomiting, severe pain in the upper part of the abdomen that can radiate to the back, and fever and a fast heartbeat. These symptoms can be a sign of pancreatitis, which is a life-threatening condition.
Speak to your doctor or pharmacist if you notice uncommon side effects. To see a full list of all possible symptoms, refer to the Mounjaro Patient Information Leaflet.
Read our guide on Mounjaro side effects to find out more.
Warnings
Mounjaro Warnings
Mounjaro may not be suitable for everyone.
Tell your prescriber if you:
- Have ever had pancreatitis
- Have serious digestive problems or delayed stomach emptying
- Have eye conditions such as diabetic retinopathy
- Are using insulin or a sulphonylurea for diabetes
- Are pregnant, breastfeeding, or planning pregnancy
Women using oral contraceptives should use a barrier method (e.g., condom) for 4 weeks after starting Mounjaro and after each dose increase.
Stay well-hydrated during treatment. Your suitability will be confirmed during the online consultation.
Related guidance:
Patient Information Leaflet
Mounjaro Weight Loss Injection Patient Information Leaflet
For more information about Mounjaro, please take a look at the information leaflet below. It is important you read the Patient Information Leaflet (PIL) before using Mounjaro.
Alternatives
Other prescription treatments are available for weight management. Your Cloud Pharmacy prescriber will help determine the most suitable option during your free consultation.
Common Alternatives
- Wegovy (semaglutide) - Once-weekly injection in the same GLP-1 family as Mounjaro.
- Saxenda (liraglutide) - Daily injection that helps reduce appetite.
- Orlistat - Oral capsules that reduce fat absorption.
- Mysimba - Oral tablets that act on appetite control in the brain.
Need help comparing options?
Review Date
1 January 2025
Next Review
1 January 2026
Published on
14 June 2023
Last Update
19 February 2026
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Am I eligible?
Mounjaro pricing
If you’re currently using Mounjaro (or have recently used it) you can buy the step-up or maintenance doses through Online Mens Clinic.
| Price | |
| Mounjaro 2.5mg | £164.99 |
| Mounjaro 5mg | £174.99 |
| Mounjaro 7.5mg | £234.99 |
| Mounjaro 10mg | £259.99 |
| Mounjaro 12.5mg | £274.99 |
| Mounjaro 15mg | £294.99 |
Mounjaro Weight Loss Injection FAQs
Medically reviewed on January 1st, 2025
What is Mounjaro and how does it work for weight loss?
Mounjaro contains tirzepatide, a prescription medicine that mimics two natural hormones (GLP-1 and GIP). These hormones help regulate blood sugar and appetite, which can reduce cravings, slow stomach emptying, and make it easier to eat less. Combined with a balanced diet and exercise, this can support meaningful weight loss.
Who can take Mounjaro?
Mounjaro is licensed for adults aged 18 and over who have a BMI of 30 or above, or a BMI of 27 or above with a weight-related condition such as high blood pressure, high cholesterol, or type 2 diabetes. Eligibility is confirmed after a free online consultation with a Online Mens Clinic prescriber.
How much weight can I lose with Mounjaro?
In clinical studies, patients taking Mounjaro alongside diet and exercise lost up to 15–20% of their starting weight over several months. Results vary depending on dose, lifestyle changes, and individual response.
How do you take Mounjaro?
Mounjaro is a once-weekly injection using a pre-filled KwikPen. The pen is self-administered under the skin of the stomach, thigh, or upper arm. Each pen is supplied with needles and detailed instructions.
What is the recommended Mounjaro dosage?
Treatment usually starts at 2.5 mg once a week and increases gradually as required at a minimum of every 4 weeks
How quickly does Mounjaro start working?
Some people notice reduced appetite within the first few weeks, but weight loss typically becomes more visible after 4–8 weeks and continues as the dose increases.
What are the common side effects of Mounjaro?
The most frequent side effects are nausea, vomiting, indigestion, diarrhoea, constipation, and reduced appetite. These are usually mild and improve as your body adjusts. Serious side effects such as pancreatitis are rare but require immediate medical attention.
Is Mounjaro the same as Wegovy or Ozempic?
Mounjaro is in the same GLP-1 family as Wegovy and Ozempic but also activates a second hormone (GIP), which may lead to greater weight-loss results in clinical trials. Your prescriber can help decide which medicine best fits your needs.
Can I drink alcohol while taking Mounjaro?
Moderate alcohol is not strictly prohibited, but drinking can increase the risk of low blood sugar and may worsen stomach side effects. It’s best to limit intake and speak to your prescriber if you have questions. Read our guide that discusses Mounjaro and alcohol in detail.
Can I take Mounjaro if I’m pregnant or trying for a baby?
No. Mounjaro is not recommended during pregnancy or breastfeeding, and should be stopped at least one month before planning pregnancy. Read our guide that discusses Mounjaro and pregnancy in detail.
Do I need to follow a special diet with Mounjaro?
No specific diet is required, but balanced meals and regular physical activity will improve results and help maintain weight loss.
What if I have type 2 diabetes?
Mounjaro can help improve blood sugar control in type 2 diabetes, but if you take insulin or other diabetes medicines, your prescriber may need to adjust your doses to avoid low blood sugar.
How do I get Mounjaro in the UK?
Mounjaro is available only on prescription from a UK-registered prescriber. With Online Mens Clinic, you complete a free online consultation and can buy Mounjaro online.
If approved, the medicine is dispensed by a registered pharmacist and delivered discreetly with next-day delivery.
Has the price of Mounjaro increased recently?
Yes. From September 2025, Eli Lilly raised UK list prices for Mounjaro by around 170%, with the highest dose rising from roughly £122 to about £330 per month. The increase reflects higher manufacturing and supply costs and brings UK pricing in line with other European markets.
If cost is a concern, speak to your prescriber about switching to an alternative such as Wegovy, which may be more affordable depending on your treatment plan. Current prices are always shown on the Online Mens Clinic product page before you begin your consultation, so you can check the latest cost before ordering.
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