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
Is 7 kg Weight Loss Noticeable?
A 7 kg weight loss (approximately 11 stone) is absolutely noticeable and represents meaningful progress for most people. At this level of weight loss, you'll typically see visible changes in how clothes fit, energy levels often improve, and health markers usually shift in a positive direction. For many UK adults, 7 kg is also significant enough to produce measurable improvements in blood pressure, blood sugar control, and joint stress. Using our free BMI calculator, you can see exactly how this amount of weight loss affects your personal BMI and health category — even modest losses often move people from one health classification to another.
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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.
Prescription Weight Management Options in the UK
For UK adults eligible for weight loss medication, prescription options can help achieve and sustain losses like 7 kg and beyond. Three main medications are licensed for weight management through the NHS and private prescribing:
- Mounjaro (tirzepatide) — dual GIP and GLP-1 receptor agonist; average weight loss 15–21% body weight in clinical trials
- Wegovy (semaglutide) — GLP-1 receptor agonist; average weight loss approximately 15% body weight
- Saxenda (liraglutide) — GLP-1 receptor agonist taken daily; similar outcomes to Wegovy
Eligibility requires a BMI of 30 or above, or 27–29.9 with weight-related health conditions such as type 2 diabetes, high blood pressure, or sleep apnoea. South Asian, Chinese, Black African, and Black Caribbean adults may qualify at lower BMI thresholds. Our GLP-1 weight loss calculator can help you estimate potential weight loss with medication alongside diet and exercise changes.
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 vs Private Access and Next Steps
NHS access is through specialist tier 3 weight management services — typically requiring a GP referral and assessment. Availability and waiting times vary significantly by region (Integrated Care Board). Private access is available through UK-licensed online prescribers following a clinical consultation, without NHS referral.
If you're interested in prescription weight loss medication, the first step is a conversation with your GP. They can assess whether you're eligible, discuss your health goals, and explain local NHS options or recommend private routes. Prescription medications work best alongside reduced-calorie diet and increased physical activity — they support weight loss, not replace lifestyle change.
- 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.
Will I definitely lose 7 kg with weight loss medication?
No — individual results vary significantly based on genetics, adherence, diet, and exercise. Clinical trials show average weight loss, but some people lose more and others less. A prescriber will discuss realistic expectations during your assessment.
How quickly can I lose 7 kg with Mounjaro or Wegovy?
The NHS recommends safe weight loss of 0.5–1 kg per week. At this rate, 7 kg would take approximately 7–14 weeks. With prescription medication alongside lifestyle changes, many people achieve this timeframe, though individual timelines vary.
What happens to my BMI if I lose 7 kg?
The BMI change depends on your current weight and height. Use our free BMI calculator to see your before and after BMI at 7 kg lighter — you'll often move into a healthier category, which typically brings health benefits.
Can I get weight loss injections on the NHS in the UK?
Yes — GLP-1 medications including Mounjaro and Wegovy are now available through NHS specialist weight management services for eligible adults. Access is through referral to tier 3 services, and availability varies by region. Private options are also available.
What's the difference between prescription weight loss and diet alone?
Prescription medications like Mounjaro and Wegovy work by reducing appetite and helping you feel fuller, making a calorie deficit easier to maintain. Combined with diet and exercise, they help more people achieve and sustain weight loss than diet alone — especially for larger losses.
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.