Mounjaro KwikPen

The Mounjaro KwikPen contains Tirzepatide, a medication that’s proven to help reduce appetite and curb cravings to support weight loss. It can also be used for weight loss maintenance once you’ve reached your weight loss goal. Buy Mounjaro Weight Loss Injection UK

• Lose up to 25% of your body weight
• 4 week supply of Tirzepatide injections per pen
• Expert on-hand weight management support

Time for a change?

Thinking about switching your weight loss treatment from Mounjaro to Wegovy? Explore our switching guide to see how.

Get to know the Mounjaro KwikPen

Using the active ingredient Tirzepatide, the Mounjaro KwikPen is part of a family of new-generation weight loss treatments. It’s licenced in the UK for weight loss and weight maintenance, where studies have shown patients can lose up to 25% of their starting body weight.

• Once a week injection with a self-administer pen
• Sourced direct from manufacturer (Eli Lilly)

Mounjaro KwikPen key facts

The pen is designed to allow you to easily self-inject Mounjaro at home once a week. It’s injected just under the skin with a small, thin needle. You can choose to inject in either your stomach area, thigh or upper arm – whichever you prefer.

Each pen lasts one month and comes pre-loaded with 4 doses (4x once weekly injections).

Always make sure to read the user instructions and the Patient Information Leaflet that comes with the device.

How do Mounjaro injections work?

Mounjaro injections work by mimicking two hormones your body naturally makes: GLP-1 (glucagon-like peptide-1) and GIP (glucose-dependent insulinotropic polypeptide). These hormones help control blood sugar levels and reduce hunger. Buy Mounjaro Weight Loss Injection UK

How Mounjaro works with your body

Mounjaro works with your body to help you lose weight. It’s most effective when used alongside a balanced, healthy diet and increased physical activity or exercise.

• Helps your pancreas make insulin: After you eat, Mounjaro tells the pancreas to release more insulin, a hormone that lowers blood sugar. Improving how your body uses insulin stops it from storing excess sugar as fat.
• Lowers the amount of sugar your liver makes: When your liver isn’t releasing sugar into the blood for energy, your body has to rely on fat stores for energy. This process, where the body breaks down its fat cells, is called lipolysis and leads to weight loss.
• Makes you feel full: Mounjaro works on the part of the brain that controls hunger, helping you feel full sooner and reducing how much you eat.
• Slows digestion: Mounjaro makes food move more slowly through the stomach, which helps prevent big spikes in blood sugar after meals and keeps you feeling full.

Understand who can use Mounjaro

Mounjaro is a prescription-only medication licenced in the UK for weight loss. This means there are guidelines on who it’s suitable for, based on a range of health factors and likelihood of successful treatment results. Buy Mounjaro Weight Loss Injection UK

It might be a suitable treatment for you if you meet the below initial eligibility criteria:

• Adults aged 18-85
• Those with a BMI above 30
• Those with a BMI above 27 and a weight-related condition such as high blood pressure, high cholesterol, heart disease, type 2 diabetes and some other weight-related health conditions

This list is only intended as an indicator for who might be suitable for treatment. The doctor will complete a full medical review of your consultation to determine your individual suitability for treatment.

Use this NHS tool to calculate your BMI.

Possible Mounjaro weight loss results

Studies have shown a possible weight loss of up to 25% over 88 weeks. Mounjaro is a long-term weight loss treatment and not just a short-term option, you should start to see weight loss within the first 4-6 weeks.

Weight loss examples

One medical trial involved 2,539 people using either a placebo, Mounjaro 5mg, Mounjaro 10mg or Mounjaro 15mg once a week for 72 weeks (just over 1 year and 4 months).

Everyone using Tirzepatide (Mounjaro) on the trial started with 2.5mg once weekly for the first four weeks. During this time, they lost around 3% of their starting body weight.

Tirzepatide users on the trial went up to 5mg once weekly for the next four weeks (weeks 5-8). During this time, users reached an average of 5-6% weight loss.

For weeks 9-12, some people stayed on 5mg of Mounjaro, and some moved up to 7.5mg weekly. Most people lost around 8% of their starting weight by week 12, regardless of whether they were on 5mg or 7.5mg.

Remember, studies show an example of what’s possible, but every weight loss journey is unique.

Our expert team is here to help you achieve your health and weight goals.

Frequently Asked Questions

Is Mounjaro better than Wegovy?

Mounjaro and Wegovy are both MHRA-approved medications for weight management, and although they both work in a similar way by reducing hunger and cravings, these weight loss injections are scientifically different.

Wegovy is a glucagon-like peptide-1 (GLP-1) receptor agonist containing Semaglutide, while Mounjaro is a dual GIP and GLP-1 receptor agonist containing Tirzepatide.

Is Ozempic the same as Mounjaro?

While they are both once-weekly injections, they are not the same. Ozempic is used to treat diabetes, produced by Novo Nordisk, and contains the active ingredient Semaglutide. Mounjaro is used for weight management. It is made by the pharmaceutical company Eli Lily and contains the active ingredient Tirzepatide.

How do I store my Mounjaro at home?

The Mounjaro KwikPen should be placed in your fridge (set between 2°C and 8°C) as soon as possible after delivery and must be kept refrigerated until you’ve opened it to administer your first injection. After that, it can be stored at room temperature (up to 30°C) for no more than 30 days, and kept out of direct sunlight and away from direct heat.

If you’re travelling, it’s recommended to keep your Mounjaro KwikPen in your hand luggage and use a cool bag with an ice pack, if needed.

How do I inject Mounjaro using the KwikPen?

You might be slightly nervous the first time you’re getting ready to inject, but the key is preparation and practice.

There are several key stages to injecting:

Preparing your dose
Injecting your dose
Post-injection
Make sure to thoroughly read and understand the user instructions that come with your KwikPen, following each step as directed.

Our top injection tips include:

Reading the user instructions thoroughly
Washing your hands before starting
Choosing your injection site carefully to avoid side effects
Giving yourself plenty of time on injection day so you aren’t rushed

Where is the best place to inject Mounjaro?

Whether you inject in your abdomen, thigh or arm doesn’t affect the effectiveness of the drug.

It is your personal preference. Some people find that the abdomen is the least painful of the three injection sites, whereas the upper leg allows more visibility for injecting compared to the arm, which is a less visible option.

If you choose the same injection site, you should make sure it’s at least one fingertip space away from where you injected the week before.

Is a red bump or liquid on my skin normal after injecting?

Yes, up to 1 in 10 people will experience redness, itching and swelling on the injection site. This is normal and these injection site reactions will disappear as your body gets used to the medicine. You can take an anti-histamine tablet and apply a cooling compress to the area to help treat this.

If for any reason these reactions become more severe, you should contact your healthcare provider right away as it may be a sign of a more severe allergic reaction.

Surplus liquid

Seeing liquid on the skin after injecting Mounjaro is normal and is commonly referred to as leakage or backflow.

It can be caused by many factors such as injection speed, volume of solution or the angle you insert the needle.

You must ensure that you leave the needle in the skin at least 3 seconds after injection, this should help prevent so much liquid on the skin. Never give yourself a second dose, no matter how much liquid is left on your skin.

Can I take my Mounjaro dose a day early?

Yes, you can. You can take Mounjaro up to 3 days early or more than 3 days after your last dose.

There is a small chance you might experience extra or stronger side effects when taking your next dose early, especially if you are also going up a strength. This isn’t a problem, but you should be aware.

This table shows the earliest you can take your next dose based on your current regular Mounjaro day.

Current Mounjaro Day Earliest you can take next dose
Monday Friday
Tuesday Saturday
Wednesday Sunday
Thursday Monday
Friday Tuesday
Saturday Wednesday
Sunday Thursday

Can I take my Mounjaro dose a day late?

Yes, you can take Mounjaro up to 4 days late. Then inject your next dose as usual on your original scheduled day. If it is over 4 days, you must skip the missed dose. Then inject your next dose as usual on your original scheduled day.

If your usual Mounjaro day is You can still use a missed or forgotten dose on
Monday Tuesday, Wednesday, Thursday or Friday
Tuesday Wednesday, Thursday, Friday or Saturday
Wednesday Thursday, Friday, Saturday or Sunday
Thursday Friday, Saturday, Sunday or Monday
Friday Saturday, Sunday, Monday or Tuesday
Saturday Sunday, Monday, Tuesday or Wednesday
Sunday Monday, Tuesday, Wednesday or Thursday

When should I increase my dose of Mounjaro?

This all depends on how well you tolerate the dose you are on. If you are taking any strength of Mounjaro, you have no side effects and still losing weight, we advise that you stay on that dose.

On the other hand, if you have increased your dose of Mounjaro and you are experiencing unbearable side effects, you may want to consider reducing your dose.

If you have taken a dose of Mounjaro for at least 4 weeks, have no side effects and have stopped experiencing weight loss, you may have hit a weight loss plateau and could consider increasing your dose. You should reflect on your eating and exercising first.

When you request a change of dose our healthcare professionals will consider this and help you make the best and safest decision for you.

What is the magical 5th dose in a Mounjaro pen?

The “magical 5th dose” refers to the extra medication that remains in a Mounjaro pen after you’ve used the four standard doses. Each Mounjaro pen is designed and licensed to deliver four weekly injections of your prescribed dose, but some patients think there’s enough medication left over for a potential fifth injection. This isn’t the case.

The extra liquid is only there to accommodate for the liquid that may be lost during the priming stage before each weekly injection. There is not a secret 5th dose in the pen.

You should always follow the official use instructions, as it can be unsafe to do otherwise.

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The pen isn’t designed to deliver a full fifth dose
You wouldn’t be getting the correct amount of medication
Mounjaro is licensed and optimised for four doses per pen only

Is there an ideal diet to follow during weight loss treatment?

Whilst there isn’t a specific diet to follow, it’s recommended that you follow a healthy & balanced diet. Focus on creating balanced meals that contain adequate protein and fibre. Make sure to drink plenty of fluids too.

You should drink at least 6 – 8 servings of water a day (one serving is a 250ml glass).

Try to avoid drinking with meals as this can cause you to feel too full and stop you from being able to eat your meal. We advise drinking water at least 30 minutes before or after a meal.

Aim for 3 meals a day, with snacks in between if needed, to provide your body with steady energy throughout the day. A balanced meal should look like:

Filling half your plate with non-starchy vegetables, salad or fruit
Filling a quarter with wholegrain carbohydrates
Filling the other quarter with lean protein
Include a small serving of healthy fats within your meal

What vitamin supplements should I take on Mounjaro?

One of the most important steps while using weight loss injections is maintaining a balanced, nutrient-rich diet. Even though you’re eating less, choose foods that provide the essential vitamins & minerals your body needs. Prioritise lean proteins, colourful vegetables, whole grains and healthy fats to support your overall health during weight loss.

Rapid weight loss can sometimes lead to side effects like temporary hair loss if your body isn’t getting enough nutrition. By focusing on nutrient-dense meals, you can help minimise these effects naturally.

If you’re finding it challenging to meet your nutritional needs through food alone, oral vitamin supplements can provide additional support:

Daily multivitamin – to cover any nutritional gaps from reduced food intake
Biotin, zinc, and selenium (often found in skin, hair and nails formulas) – may help support hair health during weight loss
Vitamin B complex and iron – can help combat tiredness from lower calorie intake
Remember, supplements should complement a healthy diet, not replace it. If you’re concerned about your nutritional intake or experiencing side effects, let us know during your next consultation or contact our team here.

What is the best exercise to do on Mounjaro?

Any exercise is great and it’s important to move your body daily. This might be something you need to build up to, and to get the best results from your weight loss journey you should consider a range of different exercise types. Try light aerobatic exercises like walking / brisk walking or jogging, and strength training such as lifting weights and doing squats to help build muscle and boost your metabolism.

Does the pill stop working when taking Mounjaro?

The effectiveness of oral contraceptive pills can be reduced by up to 20% when using Mounjaro for weight loss. Oral contraceptives need to be absorbed by the body to work, but because Mounjaro slows down the emptying of the stomach (and may cause diarrhoea in some patients), this can reduce absorption and the reliability of the pill.

It’s advised to use a barrier method of protection (such as condoms) when using Mounjaro, and especially in the first 4 weeks after you start treatment or increase dose levels. If you’re increasing dose levels every month, you may need to consider a longer term contraceptive barrier method.

Can I take Mounjaro if I’m trying to get pregnant?

If you become pregnant while taking Mounjaro, you should stop immediately and let your doctor know you’ve been taking it.

Do I have to stay on Mounjaro long term?

According to studies, Mounjaro is most effective if it is taken continuously for 12 months or longer.

After 12 months, you can also decide whether you will stop treatment or stay on a maintenance dose.

You can stop Mounjaro at any point in your treatment, this is completely up to you. If you stop treatment we advise that you continue to maintain a healthier lifestyle to prevent any unwanted weight gain.

You can speak to a member of our trained team if you have any questions about stopping or continuing your treatment with Mounajro.

What is a Mounjaro maintenance dose?

A Mounjaro maintenance dose is the dosage you continue taking once you’ve reached your weight loss goals or found the dose that works effectively for you.

Your maintenance dose is determined by several factors: how well you’re tolerating the medication, the weight loss results you’re achieving, and any side effects you experience. Some people maintain their results on lower doses like 5mg or 7.5mg, while others may need the maximum dose of 15mg to sustain their weight loss.

Remember, Mounjaro is most effective when combined with a healthy diet and regular exercise, regardless of your maintenance dose.

What happens when you stop taking Mounjaro?

When you stop using Mounjaro, you will notice your appetite increasing or returning in full within a few weeks. If you haven’t made any necessary lifestyle adjustments, you could regain some of the weight you lost. Regular exercise and healthy eating are two ways to stay on top of your weight loss and prevent regaining it.

Many patients also opt to take a maintenance dose, which is usually a lower dose level and helps them maintain their weight loss over the longer term.

There are not any reports of people experiencing withdrawal symptoms when discontinuing the use of Mounjaro. The medicine can take up to 25 days to entirely leave your system, so any side effects you are experiencing should also go by then.

Can I switch from Mounjaro to Wegovy?

Some patients are able to switch, but just because you’ve been prescribed Mounjaro, it doesn’t mean you can automatically switch to Wegovy. Explore our dedicated switching page to see if it might be suitable for you. Buy Mounjaro Weight Loss Injection UK

Is there a washout period if I switch from Mounjaro to Wegovy?

Yes, but this should be done under medical supervision with a proper “washout” period. This means letting the current treatment flush out of your system before switching to a different treatment. The length of the washout period depends on which medication you’re taking, the severity of any side effects and the dose level. Explore our dedicated switching page for more information.

Why have the prices of Mounjaro risen so much?

Eli Lilly – who make Mounjaro – increased their prices across all strength levels from 1st September 2025. This means they are charging more per pen and this is affecting every Mounjaro KwikPen retailer – Buy Mounjaro Weight Loss Injection UK