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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How Much To Eat On Mounjaro: Appetite, Cost & UK Access
One of the main effects of Mounjaro is that it naturally reduces your appetite — so you'll typically want to eat less, and feel satisfied with smaller portions. This guide covers how appetite changes on Mounjaro, what you might expect to eat, UK prescription costs, and how to access tirzepatide either privately or through the NHS. All prescription weight loss treatment requires a clinical assessment from a UK-licensed prescriber.
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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.
How Mounjaro Affects Your Appetite and Eating Patterns
Mounjaro (tirzepatide) is a dual GIP and GLP-1 receptor agonist that works partly by signalling to your brain that you are satisfied after eating smaller amounts of food. You don't follow a specific meal plan — instead, your natural appetite is reduced, and you're likely to eat less without conscious restriction.
What to expect:
- Reduced hunger and food cravings, especially for high-calorie or sweet foods
- Feeling full after smaller meals — typically 30–50% less food than before
- Slower eating speed and earlier satiety signals
- Nausea in the first few weeks (common and usually improves) may further reduce appetite temporarily
- Food aversions — some foods may become less appealing
You should eat a balanced, nutritious diet with adequate protein and vegetables. Eating too little risks muscle loss and nutritional deficiency. Many users of GLP-1 and GIP/GLP-1 medications find they naturally make better food choices because highly processed foods feel less appealing.
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.
UK Prescription Cost and Access Routes for Mounjaro
Private prescription route: Mounjaro is available through UK-licensed online prescribers following a clinical assessment. Costs typically range from £129–£320 per month depending on your dose — the KwikPen contains 4 weekly injections. You don't need an NHS referral. Most prescribers require a consultation fee (usually £20–£50) plus the medication cost. Delivery usually takes 3–5 working days.
NHS route: Tirzepatide is available through NHS specialist tier 3 weight management services, but access varies significantly by region. You'll need a GP referral and assessment by the specialist service. Waiting times can be several months to over a year in many areas depending on local capacity and demand.
- 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.
Does Mounjaro mean I can eat whatever I want, just less?
No. While Mounjaro reduces appetite, you still need to eat a balanced diet with adequate protein, vegetables, and nutrients. Eating too little can cause muscle loss and nutritional deficiency. The medication supports healthier choices — most people naturally gravitate toward more nutritious foods because processed foods become less appealing.
How much will I spend on Mounjaro in the UK privately?
Private Mounjaro costs typically £129–£320 per month depending on your dose. A KwikPen contains 4 weekly injections. Add a consultation fee (usually £20–£50) at the start. Most users stay on a consistent dose after titration, so monthly costs remain predictable. Total annual cost ranges from approximately £1,500–£3,850.
Can I get Mounjaro on the NHS in the UK?
Yes, but it's limited. Tirzepatide is available through NHS specialist weight management services (tier 3), but access varies by region and waiting lists are often long. You'll need a GP referral and assessment by the specialist service. Many regions have very limited capacity, so private prescription is often faster.
What's the difference between Mounjaro and Wegovy for cost and access?
Mounjaro and Wegovy (semaglutide) both cost roughly £129–£320/month privately, depending on dose. Mounjaro is a dual GIP+GLP-1 agonist; Wegovy is GLP-1 only. Clinical trials show Mounjaro may provide slightly greater average weight loss. Both are prescription-only and available through private prescribers or NHS specialist services.
Will I need to count calories on Mounjaro?
Not strictly. Mounjaro reduces appetite so you naturally eat less without conscious calorie counting. However, many people find that tracking their eating — using our free GLP-1 weight loss calculator or progress tracker — helps them stay motivated and ensures they're eating enough nutrition. Your prescriber may also recommend tracking to support your weight loss goals.
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.