The UK's most complete GLP-1 guide
Every Question Answered. Every Side Effect Explained.
- How GLP-1 medications work
- Mounjaro vs Wegovy compared
- Injection instructions
- Side effects & solutions
- What to eat on treatment
- FAQs answered
Free tracker included with every download this week
Travelling With Mounjaro — What You Need to Know
If you're taking Mounjaro (tirzepatide) and planning to travel, it's important to know how to store and manage your KwikPen safely while away. Whether you're travelling within the UK or internationally, your prescription medication needs proper care to remain effective. This guide covers storage requirements, what to pack, customs considerations, and practical tips to help you travel confidently with your once-weekly injection.
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Enter your height and weight below. Supports both imperial (stone & lbs) and metric (kg). Results include NHS category, healthy weight range, and ethnicity adjustments.
What Is BMI and Why Does It Matter?
Body Mass Index (BMI) is the most widely used screening tool for assessing whether your weight falls within a healthy range. Used by the NHS, GPs, and weight management services across the UK, BMI provides a quick snapshot of your weight relative to your height. The formula is simple: your weight in kilograms divided by your height in metres squared (kg/m²).
While BMI isn't a perfect measure — it doesn't account for muscle mass, bone density, or fat distribution — it remains the standard first step in identifying potential weight-related health risks including type 2 diabetes, cardiovascular disease, high blood pressure, and certain cancers.
The NHS also recommends adjusted thresholds for people of South Asian, Chinese, or Black African heritage — a BMI of 23 or above is classified as overweight, and 27.5 as obese. Our calculator includes this adjustment as a one-click toggle.
Storage Requirements When Travelling
Unopened Mounjaro pens must be kept refrigerated between 2°C and 8°C until first use. If travelling, use an insulated travel case or portable cooler bag with ice packs to maintain this temperature. Never freeze your pens — frozen Mounjaro cannot be used.
After your first injection, your pen can be stored at room temperature (below 30°C) for up to 30 days. This makes mid-trip injections easier — you don't need continuous refrigeration once you've started using a pen.
- Keep pens in their original carton to protect from light and heat
- Avoid direct sunlight and hot environments (beaches, cars in summer)
- Do not leave pens in checked luggage — keep them in carry-on baggage where you can monitor temperature
- Consider TSA-compliant cooling packs or ask your pharmacy for travel-appropriate storage advice
When travelling across time zones, maintain your once-weekly schedule by injecting on the same day of the week — your prescriber can advise if you need to adjust timing slightly for your destination.
Clinically BackedWeight Loss
No appointments. No waiting rooms. Just care — from a UK-regulated online pharmacy.
How It Works
Three simple steps to understand your weight and take action.
Enter your height and weight in our free calculator. Get your BMI, NHS category, healthy weight range, and ethnicity-adjusted thresholds instantly.
If your BMI suggests you're overweight or obese, explore our GLP-1 calculators to project potential weight loss on Mounjaro or Wegovy.
Use our progress tracker to log your weight weekly, visualise your journey with charts, and stay motivated — all stored privately in your browser.
Free Weight Loss Tools & Guides
Everything you need to understand your weight, explore medication options, and track your progress — completely free.
Flying and Customs — What You Need
Prescription Mounjaro is permitted in carry-on and checked baggage on UK and EU flights, but always carry your original prescription or a letter from your GP confirming you have a valid prescription. This protects you at customs and reassures airport staff.
Inform security staff you are carrying prescription medication — they may request to see your pens and documentation. Keep your medication in a clearly labelled bag with your prescription details visible.
If travelling internationally, research the destination country's regulations — some nations restrict import of certain medications. Contact the embassy of your destination country before travelling, or ask your prescriber for a letter confirming your clinical need.
Keep contact details for your UK prescriber and a copy of your prescription with you at all times, in case you need to show it to healthcare providers abroad.
- Dual GIP/GLP-1 receptor agonist
- Up to 22.5% body weight loss (SURMOUNT-1)
- Weekly injection, dose escalation over 20+ weeks
- Available via private prescription in the UK
- Doses: 2.5mg → 5mg → 7.5mg → 10mg → 12.5mg → 15mg
- GLP-1 receptor agonist
- Up to 15–17% body weight loss (STEP trials)
- Weekly injection, 5-step dose escalation
- NHS & private prescription available
- Doses: 0.25mg → 0.5mg → 1mg → 1.7mg → 2.4mg
Mounjaro vs Wegovy: Head-to-Head
A side-by-side comparison of the two most popular GLP-1 weight loss medications available in the UK.
| Feature | Mounjaro | Wegovy |
|---|---|---|
| Drug class | Dual GIP/GLP-1 agonist | GLP-1 agonist |
| Active ingredient | Tirzepatide | Semaglutide |
| Avg. weight loss | 15–22.5% | 12–17% |
| Key trial | SURMOUNT-1 (2022) | STEP 1 (2021) |
| Max dose | 15 mg weekly | 2.4 mg weekly |
| Escalation period | 20–32 weeks | 16–20 weeks |
| Administration | Weekly injection (pen) | Weekly injection (pen) |
| NHS availability | Private prescription only | NHS & private |
| Approx. private cost | £150–£250/month | £150–£300/month |
| Common side effects | Nausea, diarrhoea, constipation | Nausea, vomiting, diarrhoea |
Data sourced from SURMOUNT-1 and STEP 1 clinical trials. Costs are approximate and vary by provider. Always consult a prescriber.
Am I Eligible for Weight Loss Medication?
In the UK, eligibility for GLP-1 weight loss medications like Mounjaro and Wegovy is based on your BMI and overall health profile.
- BMI of 30 or above (obese)
- Age 18 or over
- No contraindicated conditions
- Committed to lifestyle changes
- BMI of 27 or above
- Plus type 2 diabetes
- Or high blood pressure
- Or obstructive sleep apnoea
Use our BMI calculator to check whether your BMI falls within the eligible range.
How We Built These Tools
Every calculator and guide on myweightcheck is built with accuracy and transparency in mind. Our BMI calculator uses the standard WHO formula with NHS-aligned category thresholds. Our GLP-1 projections are modelled on published clinical trial data from SURMOUNT and STEP studies.
All data stays on your device. We don't require sign-ups, and we don't store your health information on any server. Your progress tracker saves data locally in your browser using localStorage, so only you can see it.
We're based in the UK and our tools are designed specifically for UK users — supporting stone & lbs by default, referencing NHS guidelines, using NICE-approved medication data, and linking to GPhC-registered pharmacies.
Frequently Asked Questions
Common questions about BMI, weight loss medications, and our free UK tools.
Can I travel with my Mounjaro KwikPen on an aeroplane?
Yes — Mounjaro is permitted in both carry-on and checked baggage. Always carry your original prescription or a GP letter confirming your prescription. Show documentation to security staff if asked, and keep your pens at the appropriate temperature during travel.
How do I keep my Mounjaro cold when travelling?
Use an insulated travel case or portable cooler bag with reusable ice packs. Unopened pens need 2–8°C; once you've injected, your current pen can stay at room temperature (below 30°C) for up to 30 days, making travel easier mid-trip.
What should I do if my Mounjaro freezes during travel?
Do not use frozen Mounjaro — it cannot be restored to working condition. If your pen has frozen, contact your prescriber or pharmacy immediately to arrange a replacement, as you may not be able to take your scheduled injection.
Do I need special documentation to travel abroad with Mounjaro?
Yes — carry your original prescription and ideally a letter from your GP. Research the destination country's medication regulations before travelling, as some nations restrict import of certain medications. Contact the embassy of your destination country for clarity.
How do I manage my injection schedule when crossing time zones?
Keep to your regular once-weekly injection day (same day of the week). Your prescriber can advise if you need to adjust timing slightly due to your destination, but you should not skip doses or inject twice in one week to compensate.
Ready to take control of your weight loss journey?
Start with a free BMI check, explore your GLP-1 options, or begin tracking your progress today. No sign-up. No cost. Just results.