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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What to Eat on Mounjaro: UK Dietary Guidance
When starting Mounjaro (tirzepatide), choosing the right foods can help manage side effects and support weight loss goals. Mounjaro is a prescription-only GLP-1 and GIP receptor agonist that works by reducing appetite and slowing digestion, which means certain foods will feel more satisfying and others may cause discomfort. This guide covers practical dietary advice for UK adults taking Mounjaro, alongside information about accessing this treatment through NHS specialist services or private prescription routes in the UK.
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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.
Foods to Prioritise and Foods to Avoid on Mounjaro
When taking Mounjaro, lean towards protein-rich, nutrient-dense foods that are easier to digest and keep you satisfied with smaller portions. Good choices include grilled chicken, fish (especially fatty fish rich in omega-3s), eggs, Greek yoghurt, cottage cheese, lentils, and beans. Include plenty of non-starchy vegetables—broccoli, spinach, peppers, courgettes, and carrots—as these are filling yet low in calories.
Avoid or minimise foods that commonly trigger side effects: fried and greasy foods, sugary drinks and desserts, high-fat dairy products, and processed snacks. These can worsen nausea, vomiting, and diarrhoea. Portion sizes matter significantly—many people find they need far less food to feel full on Mounjaro, so eating slowly and stopping when comfortably satisfied (not stuffed) is essential.
- Sip water regularly—aim for at least 2 litres daily
- Eat 5–6 small meals rather than 3 large ones
- Ginger tea or peppermint may help with nausea
Clinically BackedWeight Loss
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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.
Mounjaro Accessibility and Cost in the UK
Mounjaro is available through two main routes in the UK. NHS access is through specialist tier 3 or 4 weight management services—you'll need a GP referral and assessment by a dedicated weight management team. Availability varies significantly by region, and waiting lists can be lengthy. Private prescription access is available through online consultations with UK-licensed prescribers, dispensed by GPhC-registered pharmacies, without requiring an NHS referral.
Private costs typically range from £129–£320 per month depending on your dose (starting 2.5 mg weekly, escalating to 15 mg maximum). Your prescriber will assess whether Mounjaro is suitable based on your BMI, health history, and any weight-related conditions. Use our free GLP-1 weight loss calculator to estimate potential outcomes, and our BMI calculator to check your eligibility range.
- 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 eat normally on Mounjaro?
No, most people find their appetite significantly reduced on Mounjaro. Portion sizes typically become much smaller—many describe feeling comfortably full after a few bites. This is the intended effect. Eating slowly and stopping when satisfied, rather than finishing your plate, is important to avoid discomfort and nausea.
What about alcohol and caffeine on Mounjaro?
Alcohol can worsen nausea and dehydration on Mounjaro, so minimise intake and always eat something first. Caffeine on an empty stomach may trigger stomach upset. Strong tea or coffee with food is usually fine, but listen to your body and reduce intake if it causes discomfort.
Will I have deficiencies if I eat less on Mounjaro?
Potentially, if you're eating significantly less. Prioritise nutrient-dense foods—proteins, leafy greens, fish, and eggs—over empty calories. Consider mentioning your Mounjaro use to your GP, who may recommend a vitamin D, B12, or iron check if you're on treatment long-term.
How do I access Mounjaro privately in the UK?
Complete an online health assessment with a UK-licensed prescriber, who will evaluate your BMI and medical history. If approved, a prescription is issued and dispensed by a GPhC-registered pharmacy. The process typically takes 24–48 hours. Costs range from £129–£320 monthly depending on dose and provider.
Is Mounjaro available on the NHS?
Yes, through specialist weight management services (tier 3/4) if you meet eligibility criteria (BMI 30+ or 27+ with weight-related health conditions). You'll need a GP referral and specialist assessment. NHS availability and waiting times vary significantly by region—contact your local integrated care board for details.
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.