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
Mounjaro Hacks: NHS-Approved Tips for UK Users
"Mounjaro hacks" aren't secret shortcuts — they're practical, evidence-based strategies to help you get the most from tirzepatide if you're prescribed it on the NHS or privately in the UK. This guide covers NHS eligibility, managing side effects, optimising your injection routine, and supporting your weight loss journey alongside lifestyle changes. These tips are informational only and should always be discussed with your prescriber or GP.
10,000+ calculations today · NHS-aligned thresholds · 100% free
Calculate Your BMI Instantly
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.
Understanding Mounjaro Eligibility and NHS Access in the UK
In the UK, Mounjaro (tirzepatide) eligibility depends on your BMI and health conditions. You may be eligible if you have a BMI of 30 or above, or 27–29.9 with weight-related conditions like type 2 diabetes, high blood pressure, or sleep apnoea. For adults of South Asian, Chinese, Black African, or Black Caribbean heritage, lower BMI thresholds apply (27.5+). NHS access is through tier 3 specialist weight management services — not standard GP prescription. NICE has approved tirzepatide for use within NHS services, but availability and waiting times vary significantly by region and Integrated Care Board (ICB). Many areas have substantial waiting lists. Private access is available through GPhC-registered online pharmacies following clinical assessment. Use our free BMI calculator to check where you fall on the NHS scale.
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.
Practical Tips for Managing Mounjaro Successfully
Key strategies include: starting with the lowest dose (2.5 mg) to allow your body to adjust; staying hydrated — nausea and constipation are common, and water intake helps manage both; eating smaller, protein-rich meals to support fullness and reduce stomach discomfort; rotating injection sites weekly to prevent irritation; and keeping a progress tracker to monitor weight loss and side effects over time. If nausea is severe, eating ginger biscuits or sipping ginger tea before meals may help. Avoid high-fat foods early on, as these can trigger nausea. Allow at least 4 weeks at each dose before expecting noticeable appetite suppression — dose titration is gradual by design.
- 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 get Mounjaro on the NHS in the UK?
Yes, NICE has approved tirzepatide for NHS use through tier 3 specialist weight management services. You'll need referral from your GP, and eligibility depends on your BMI and health conditions. Availability and waiting times vary significantly by region. Private access is also available through licensed online prescribing services.
What's the difference between Mounjaro and Wegovy in the UK?
Both are prescription-only weekly injections for weight management. Mounjaro (tirzepatide) is a dual GIP and GLP-1 receptor agonist; Wegovy (semaglutide) is a GLP-1 agonist only. In clinical trials, Mounjaro showed average weight loss of 15–21% of body weight, compared to around 15% for Wegovy. Individual results vary significantly.
How long does it take to see weight loss results on Mounjaro?
Most people begin noticing appetite suppression within 2–4 weeks of starting, but meaningful weight loss typically takes 8–12 weeks as your dose is gradually increased. Clinical trials ran for 72 weeks, so patience is important. Results vary between individuals, and lifestyle changes alongside the medication are essential.
What should I do if I experience severe nausea on Mounjaro?
Nausea is very common, especially in the first 4 weeks and when increasing doses. Contact your prescriber or GP if nausea is severe or persistent. Practical strategies include eating smaller meals, avoiding fatty foods, staying hydrated, and eating ginger biscuits. Your prescriber may recommend anti-nausea medication if needed.
Can I use Mounjaro alongside other weight loss methods?
Yes — in fact, Mounjaro works best alongside a reduced-calorie diet and increased physical activity. It's a tool to support lifestyle changes, not a replacement for them. Discuss any other weight loss supplements or methods with your GP or prescriber to ensure they're safe to combine.
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.