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
Can I Take Mounjaro On A Plane?
Yes, you can take Mounjaro on a plane when travelling from or within the UK, but you need to follow specific rules. Mounjaro is a prescription injectable medication, and the Civil Aviation Authority (CAA) has clear guidelines for transporting medicines and sharps on aircraft. Whether you're flying within the UK or internationally, understanding these rules ensures safe, hassle-free travel with your tirzepatide injection pens.
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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.
UK Rules For Carrying Mounjaro On A Plane
In your hand luggage (cabin bag): You can carry your Mounjaro KwikPen pens in your hand luggage if you have a valid prescription and a letter from your GP or prescriber. The CAA allows essential prescription medications in carry-on bags.
What you need:
- Original prescription or a letter from your prescriber confirming the medication, dose, and your name
- Original packaging or a letter stating the medication name (tirzepatide) and dosage
- Keep the sharps container clearly labelled
In checked luggage: Mounjaro can also be packed in your checked bag, though carrying it in hand luggage is generally safer. If storing in checked baggage, ensure pens are in original packaging and clearly labelled.
Storage during flight: Keep your Mounjaro pens at room temperature (below 30°C) during the flight. Aircraft cabin temperatures are stable, so this is usually not an issue for a typical flight duration.
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.
International Travel And Mounjaro
If you're travelling internationally, additional rules may apply. Some countries have strict regulations on importing prescription medications — even for personal use. Before travelling outside the UK, contact the destination country's customs authority to confirm Mounjaro is permitted. Many European countries allow personal prescription medications, but Australia, USA, and some Asian countries have stricter rules.
For EU and most European destinations: A UK prescription letter is usually sufficient. For non-EU travel: Request a letter from your GP or prescriber on headed paper, confirming the medication is prescribed to you personally. Always carry your original prescription and medication packaging. Allow extra time at airport security for inspection.
Keep contact details for your UK prescriber with you — if your medication is questioned at security, having this information helps. If you're taking Mounjaro (tirzepatide) as part of a weight loss programme, use our GLP-1 weight loss calculator before and after your trip to track whether your routine changes affect your progress. For specific eligibility and dosing information, remember that Mounjaro is prescription-only in the UK and available through NHS specialist services or private clinical assessment.
- 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.
Do I need special documentation to carry Mounjaro on a plane?
Yes. You need your original prescription or a letter from your GP or prescriber (on headed paper) confirming the medication name (tirzepatide), dose, and that it is prescribed to you. Keep this with your Mounjaro KwikPen at all times. This documentation satisfies CAA requirements and airport security.
Can I carry Mounjaro in my hand luggage or must it go in checked baggage?
You can carry Mounjaro in your hand luggage (cabin bag) with proper documentation. This is actually safer than checked baggage because you maintain temperature control. Mounjaro must be stored below 30°C, and cabin temperatures are stable. Never pack it in checked luggage without also having a backup plan if baggage is delayed.
What if I'm flying to a non-UK destination with Mounjaro?
Contact the destination country's customs authority before travelling — regulations vary significantly. EU countries generally allow personal prescription medications with UK prescriptions. Non-EU countries (USA, Australia, Canada) may have stricter rules. Always request a letter from your prescriber on headed paper confirming the medication is for your personal use, and carry original packaging and your UK prescription.
Will airport security confiscate my Mounjaro injection pen?
Unlikely, provided you have proper documentation. Show security staff your prescription letter and original medication packaging. Insulin pens and other prescription injectable medications are commonly allowed through airport security worldwide. If questioned, explain it is a prescription weight loss injection (tirzepatide). Allow extra time at security for inspection.
How should I store Mounjaro during my flight?
Mounjaro should be stored below 30°C. Aircraft cabin temperatures are typically stable and well-regulated, so this is not usually an issue during flight. Keep your pens in your hand luggage in their original packaging. If the flight is very long (over 8 hours) and you're concerned about temperature, keep them in your bag rather than exposed. After landing, return them to appropriate storage — either a fridge (2–8°C if unopened) or room temperature (below 30°C if in use).
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.