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
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Traveling With Mounjaro: UK Storage and Prescription Guide
If you're prescribed Mounjaro (tirzepatide) and planning to travel, you'll need to plan ahead to keep your injections safe and ensure you have your prescription documentation. Mounjaro requires careful storage between 2°C and 8°C when unopened, and this can present challenges when travelling abroad. This guide covers everything UK patients need to know about transporting Mounjaro, managing doses while away, customs regulations, and what to do if you lose a pen or need an emergency prescription while travelling.
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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 and Transport Requirements for Mounjaro While Travelling
Mounjaro must be stored in a refrigerator at 2°C to 8°C when unopened. Once you've started using a pen, you can keep it at room temperature (below 30°C) for up to 30 days. This creates specific challenges when travelling.
For flights and travel:
- Carry unopened pens in a cooling bag or travel cooler with ice packs or cooling elements designed for medicines
- Never freeze Mounjaro — if it freezes, do not use it
- Keep pens in their original carton away from direct sunlight and heat
- Inform airline staff during check-in that you're carrying prescription medication requiring temperature control
- In-use pens (started within the last 30 days) can be kept in a small cool bag but do not need refrigeration
- TSA-style cooling packs comply with most airline cabin baggage rules — check with your specific airline before you travel
Pack your Mounjaro pens in your carry-on luggage, never checked baggage, to maintain temperature control and prevent loss or damage.
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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.
NHS Prescriptions, Customs, and Practical Travel Planning
Before travelling, request a copy of your prescription from your GP or prescriber — this helps if you need emergency access to medication abroad. Check whether you're travelling to a country where Mounjaro is licensed; some countries may not recognise UK prescriptions.
Customs and travel documentation:
- Carry your prescription documentation and a letter from your prescriber confirming the medication, dose, and medical necessity
- Keep Mounjaro in its original packaging with the label visible
- Declare all medications at customs if required
- Contact your destination country's health authority before travelling if you're unsure about regulations
If you lose a pen or run out of Mounjaro while abroad, contact your prescriber or the UK pharmacy that supplied your medication — they may be able to advise on emergency access or arrange a replacement prescription. Travel insurance should cover prescription medications.
- 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 fly with Mounjaro in my hand luggage?
Yes. Mounjaro must always travel in your carry-on luggage, never checked baggage, to maintain temperature control. Inform airline staff during check-in that you're carrying prescription medication requiring cooling. Use an insulated travel cooler with cooling packs to keep unopened pens at 2–8°C throughout your journey.
Do I need a letter from my GP to travel with Mounjaro?
It's strongly recommended. Request a letter from your prescriber confirming your medication name, dose, medical necessity, and prescription details. This helps if customs questions your medication or you need emergency access abroad. Keep it with your original prescription documentation.
What happens if Mounjaro gets too warm while travelling?
If unopened pens get too warm (above 8°C for extended periods), they may be damaged. If frozen, do not use them. Check pens visually before use — discard any that appear cloudy, discoloured, or contain visible particles. If you're unsure whether a pen is safe, contact your prescriber before injecting.
Can I get Mounjaro prescribed while travelling abroad?
This depends on the country and whether Mounjaro is licensed there. Some countries have different approval statuses. Before travelling, arrange your prescription timing so you have enough doses for your trip, or contact your UK prescriber to discuss your plans — they may be able to advise on emergency access.
How many Mounjaro pens should I pack for a long trip?
Pack all pens needed for your trip duration, plus one or two extra in case of damage or loss. Each KwikPen contains 4 weekly doses (4 weeks supply). For a 2-week trip, you'd need at least 2 pens. Always keep extras in your cool bag, stored separately from your current in-use pen.
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.