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
How To Get Mounjaro If You're Not Obese
You don't have to be obese to access Mounjaro in the UK. The NHS and private prescribers can approve prescription weight loss medication for adults who are overweight with certain health conditions. Understanding the eligibility criteria and the health conditions that qualify is the first step. Use our free BMI calculator above to check where you currently fall, then explore whether you might qualify for treatment through your GP or a private prescriber.
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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.
Weight-Related Health Conditions That May Qualify
In the UK, Mounjaro can be prescribed to adults with a BMI of 27 to 29.9 (the overweight threshold) if you have at least one weight-related health condition. These conditions include type 2 diabetes or prediabetes, high blood pressure (hypertension), abnormal blood fats (dyslipidaemia), obstructive sleep apnoea, or a history of heart attack or stroke. The NHS recognises that excess weight contributes significantly to these conditions—even modest weight loss of 5 to 10% of body weight can improve blood sugar control, reduce blood pressure, and lower cholesterol levels. For adults of South Asian, Chinese, Black African, or Black Caribbean backgrounds, the overweight BMI threshold starts at 23, reflecting higher health risks at lower body weights. Use our BMI calculator above to check if you fall within the eligible range for your ethnic background.
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.
NHS Referral Pathway and Private Options
To access Mounjaro through the NHS, ask your GP for a referral to your local tier 3 specialist weight management service. These services assess your medical history, current weight, and health conditions before prescribing. However, NHS waiting lists can be very long—sometimes months or years depending on your region. Alternatively, you can seek a prescription through a private online prescriber following a clinical assessment. Both routes require a formal clinical evaluation—Mounjaro is prescription-only and cannot be obtained without proper medical assessment. Try our GLP-1 weight loss calculator to explore potential outcomes, then discuss the right path for you with your GP.
- 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.
What's the difference between overweight and obese BMI in the UK?
According to NHS guidelines, overweight is a BMI of 25 to 29.9, while obese starts at BMI 30. However, Mounjaro eligibility doesn't require an obese BMI—you can qualify at the overweight threshold (BMI 27 to 29.9) if you have weight-related health conditions like diabetes, high blood pressure, or sleep apnoea.
Can I get Mounjaro on the NHS if I'm overweight but don't have any health conditions?
Not typically. NHS eligibility for Mounjaro usually requires either a BMI of 30 or above, or a BMI of 27 to 29.9 plus at least one weight-related health condition. Your GP can assess your individual situation and discuss what options are available.
How do ethnic backgrounds affect Mounjaro eligibility?
Adults of South Asian, Chinese, Black African, or Black Caribbean heritage have lower BMI eligibility thresholds. These groups face higher health risks from excess weight at lower BMI levels. Eligibility may begin at a BMI of 23 or higher with a weight-related condition, rather than 27.
What health conditions qualify me for Mounjaro if I'm overweight?
Type 2 diabetes, prediabetes, high blood pressure, abnormal cholesterol (dyslipidaemia), obstructive sleep apnoea, and a history of heart attack or stroke all count as weight-related conditions that may make you eligible for Mounjaro at a lower BMI.
How long does it take to get Mounjaro through the NHS?
NHS waiting times vary significantly by region. Some areas have waits of several months to over a year for tier 3 specialist weight management services. Your GP can tell you the typical wait time in your area. Private prescribing routes are often faster.
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.