Your first dose will be with you soon or might have already arrived! Here, we’ll guide you through your first checks, how to take your first dose with confidence, and what to expect as your journey truly begins.

Key Points

• First checks and storage: We’ll show you exactly what to look for when your delivery arrives and how to store your treatment properly to keep it safe and effective.
• Learn how to take your dose: Taking your first injection is a big step, and we’ll guide you through it, so you feel prepared and in control.
• It starts low for a reason: Your first dose (2.5mg) is designed to help your body adjust to treatment. We’ll explain why this matters, what you might notice, and how to manage any early side effects.

What’s in the box?

Your first delivery is an exciting milestone, but it’s important to check everything has arrived safely and is exactly as it should be. Taking a minute to do this now helps you start your journey feeling reassured and ready.

Here’s what you should find inside your order:

• 1x Mounjaro 2.5mg KwikPen
• 7x single-use needles
• 4x alcohol swabs
• 1x sharps bin
• Patient Information Leaflet (PIL)

Your first safety checks:

• Check your parcel isn’t missing anything
• Make sure your pen feels cold (but not frozen or warm)
• Confirm you’ve received the correct strength, which should be 2.5mg
• You may notice some ice has melted or there is condensation in the box, this is normal.

If anything looks damaged, doesn’t feel right, or is missing, contact our customer service team. Our advisors will be ready to help so you can get back to your journey as quickly as possible.

Tip: You should always do these checks with every order at each stage of your journey.

Storing your treatment

Now that your order has arrived and you’ve checked everything is in place, let’s make sure your pen is stored properly. A couple of simple steps now help protect your treatment and keep everything working exactly as it should.

1. Keep your pen in the fridge
Pens must be stored between 2–8°C before their first use, so they need to be kept in the fridge. Try to avoid placing it right at the back of the fridge, where it can accidentally freeze. The fridge door is often a safer spot.

If your pen does freeze or gets too warm, you’ll need to throw it away.

2. After your first dose
Once you’ve taken your first injection, your pen can be kept at room temperature for up to 30 days, provided it stays below 30°C.

A quick tip: Choose a place that’s out of direct sunlight and away from heat sources like radiators, and avoid leaving it anywhere that can get very cold.

Getting storage right is a small step, but it’s important at every stage of your journey.

Read more on storing your treatment

Taking your first dose

The next big step is taking your first dose. We understand that this can be daunting, but we’re here to make sure you’re safe and ready! Because once you’ve done it, you’ll be able to do it every time like a pro.

Your pre-injection checklist

Before you get started, there are a few simple steps you can take to feel prepared and confident.

1. Read your patient information leaflet
You won’t need to read it every time, but it’s important to go through it before your first dose so you understand your medication and how to take it safely. It also covers where to inject and the most common side effects.

2. Choose your injection site
Where you inject won’t affect how well your treatment works, so focus on picking a spot that feels comfortable for you. You can always rotate sites with your next dose.

3. Get cleaned up
Clean hands and a clean injection site go a long way in helping to prevent irritation and keep things hygienic. A quick wash and an alcohol swab are all it takes.

Taking your first injection
We provide clear, step-by-step instructions to guide you through your first dose. The process will be the same each week, so take your time and get familiar with it. You’ll feel more comfortable than you might expect, and it quickly becomes part of your routine.

Remember: It’s a quick injection, and by following the instructions, you’re setting yourself up for a smooth start. After you’ve done it once, it will feel natural.

If you have any questions or want a little extra reassurance before you begin, our team is always here to help.

Disposing of your pen

Using your treatment safely also means disposing of your needles and pen correctly. It’s quick, simple, and helps protect both you and the people around you.

Needle disposal
After each injection, carefully remove the needle and place it straight into your sharps bin. Never reuse needles or throw them in your household waste.

You have seven needles in your pack, which gives you plenty for your four weekly doses, plus a few spares just in case.

Pen disposal
Once you’ve taken your fourth and final dose, remove the needle and place it in your sharps bin. Then place the used pen into the sharps bin too.

When your sharps bin is getting full, follow your local guidance for safe collection or drop-off so it can be disposed of properly.

After your first dose: What happens next?

Once you’ve taken your first dose, you won’t notice big changes right away, and that’s completely normal. You’re starting on a lower dose to give your body the time it needs to adjust comfortably.

As your body gets used to treatment, you may begin to notice small changes, like feeling fuller sooner, thinking less about food, or finding it easier to stay on track with healthy habits. Some people also experience mild side effects at the beginning, such as nausea, bloating, or tiredness. These are usually temporary and often settle as your body adjusts.

Remember, this is a journey, not an overnight transformation. These early changes build gradually, helping you move towards weight loss that actually sticks. Be patient with yourself, trust the process, and know that every step forward counts.

1. Learn more about your whole journey

Your first few weeks are all about giving your body time to adjust to treatment. It’s not about dramatic change or overnight transformation. Instead, think of this as a settling-in period. A chance to tune into your body, see how you feel, and start building the habits that will support your progress.

We also cover what to expect on Mounjaro in more detail, helping you build a clear, realistic picture of the road ahead.

Important: Everyone’s journey is different, and that’s something to embrace. How you lose weight and respond to treatment may not look the same as someone else. What matters most is making steady progress in a way that works for you, so you can lose the weight and keep it off.

2. Get to know side effects and how to handle them

Even though you’re starting on a lower dose to help reduce side effects, they can still happen. The reassuring news is that most are mild and manageable at home and often settle as your body gets used to treatment.

We’ll cover the most common ones here and share simple ways to manage them so you can feel prepared, not caught off guard.

Remember: Side effects are possible, but they don’t happen to everyone, and serious side effects are uncommon.

Nausea

This is one of the most common early side effects and often improves after your first few injections. You can help prevent or ease it by:

• Eating smaller meals
• Avoiding high-fat foods
• Avoiding lying down straight after eating
• Sipping water regularly to stay hydrated

Constipation

Constipation can happen when starting treatment, but a few simple habits can help.

• Move your body regularly to support digestion
• Eat more fibre-rich foods like fruit, vegetables, and whole grains
• Drink plenty of water

Diarrhoea

Diarrhoea can happen as your stomach adjusts, but it’s usually temporary. To help manage it:

• Choose plain, easy-to-digest foods
• Stay well hydrated to prevent dehydration

If diarrhoea lasts longer than 3–4 days, speak to a clinician for advice.

Acid reflux and heartburn

Changes in appetite and portion size can sometimes trigger reflux. You may find it helpful to:

• Avoid spicy foods and alcohol
• Limit fizzy drinks and caffeine
• Eat smaller portions more often
• Stay upright after meals

When to get help

Serious side effects are extremely rare. But it’s important to know when to get help, just in case. Seek immediate medical advice if you:

• have severe vomiting or can’t keep fluids down
• experience ongoing diarrhoea that leads to dehydration
• notice chest pain or persistent, severe reflux
• have symptoms that worsen instead of improve

If you experience symptoms not listed here and aren’t sure what’s normal, contact your pharmacist, GP, or NHS 111 for guidance.

Read more on side effects

Get a full breakdown of Mounjaro side effects, what’s common, and when to seek medical advice.

3. Start making changes to your diet and doing more movement

Weight loss treatment works best when it’s supported by healthy habits. Taking your treatment is an important step, but it’s only one part of the bigger picture. By focusing on your nutrition and gradually increasing your movement, you’ll see better results now while building habits that last well beyond treatment.

You don’t need to change everything overnight. Small, consistent choices can make a powerful difference over time.

Nutrition

Think of this as an opportunity to nourish your body, not restrict it. Many people notice their appetite changes on treatment, so making each meal count becomes even more important. Try to focus on:

• Prioritising protein to help protect muscle and keep you feeling fuller for longer
• Adding fibre-rich foods like vegetables, fruit, and whole grains to support digestion
• Eating regularly, even if your appetite is lower
• Staying hydrated throughout the day
• Slowing down at mealtimes and stopping when you feel comfortably full

Learn more about what to eat and what to avoid on Mounjaro

Movement

You don’t need an intense workout plan to see the benefits. Start where you are and build from there. The goal is simply to move your body more often.

• Aim for regular walks, even if they’re short
• Choose movement you enjoy. You’re more likely to stick with it
• Build up gradually rather than doing too much too soon
• Add light strength-based exercises over time to support muscle mass
• Look for everyday opportunities to move more, like taking the stairs or getting up from your desk

Remember, this isn’t about perfection. It’s about progress. Every habit you start building now supports change that’s going to last.

“I always tell patients not to overly focus on the scales. In fact, I encourage patients to only weigh themselves weekly instead of daily to eliminate any extra stress, as plateaus can happen and are a totally normal part of this process.

“Another thing to keep in mind is that there are so many factors outside of what you eat that can affect your weight day-to-day, or even week-to-week. Things like hydration, digestion and your hormones all impact your weight, and can cause fluctuations.

“If you’re feeling better in yourself, whether that’s because your clothes are a bit looser, you’ve got higher energy levels, or you’re satisfied with smaller meals, this means you’re on the right track and doing fantastically.”

 Ayesha Bashir, myBMI weight loss expert

Taking the next step: increasing your dose

After your first four weeks of treatment, it will be time to increase your dose. We’ll send you an email when it’s time to request treatment, including what to do and what to expect.

Learn more about Mounjaro doses

We’re always here to help

Starting something new often comes with questions, and that’s completely normal. Whatever you’re feeling, you don’t have to navigate it alone.

Our experts are here whenever you need support, so please do not wait until something feels serious before reaching out. If it matters to you, it matters to us.

Whether you have a quick question, feel unsure about your progress, are worried you might not be eating enough, or something just does not feel right, we’re here to listen and guide you with care.

Frequently asked questions

How long do you take Mounjaro 2.5mg for?

Most patients stay on Mounjaro 2.5mg for four weeks before increasing to the next dose, 5mg.

Can I travel with my Mounjaro pen?

Yes, you can travel with your pen. Just make sure:

• you contact us for a prescription copy to show to airport security
• you do not store the pen in your suitcase, as it’s at risk of freezing in the cargo hold
• you travel with it in a see-through bag labelled medication

You should always check the rules and regulations of the country you are visiting, and the airline you are flying with. In some cases, you might be fine to just take the box with the pharmacy label.

How do I know my Mounjaro pen is safe to use?

To check your pen is safe for use, make sure:

• there are no big bubbles in the solution (you can look at the treatment window)
• the liquid in the pen has not frozen
• the treatment is not discoloured

If you have any concerns or if anything looks tampered with, you should not use the pen and contact the customer care team.

Summary of starting Mounjaro

“Starting Mounjaro 2.5mg is an exciting step in your weight loss journey. You may feel nervous and have a lot of questions. But we’re here to support you every step of the way.

“Remember, it’s all about setting yourself up for lasting, sustainable change, not rapid weight loss. Building a routine, introducing movement and educating yourself on how the treatment works at this early stage can all help you achieve your long-term goals.”

 Ayesha Bashir, myBMI weight loss expert