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 3 Stone Weight Loss Noticeable?
Yes, losing 3 stone (42 lbs or approximately 19 kg) is very noticeable. Most people will see visible changes in how clothes fit, body shape, and overall appearance. Beyond the visible changes, a 3-stone loss typically brings measurable health improvements including better blood pressure, improved blood sugar control, and reduced joint pain. For many people, this represents around 10–clinically studied weight loss — a threshold where real health benefits become apparent. Whether you're pursuing weight loss through lifestyle changes alone or considering UK prescription weight management options like Mounjaro or Wegovy, understanding what 3 stone means for your health is important.
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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.
UK Prescription Weight Loss Options
If you're exploring prescription weight loss medication in the UK, several options are now available through NHS specialist services or private prescribing. Mounjaro (tirzepatide) is a once-weekly injection that works via dual GLP-1 and GIP pathways, while Wegovy (semaglutide) is a GLP-1-only injection, also given once weekly. Both are available for adults with a BMI of 30 or above, or 27–29.9 with weight-related health conditions such as type 2 diabetes, high blood pressure, or heart disease.
Clinical trials show that Mounjaro users lose an average of 15–21% of body weight, whilst Wegovy users average around 15% — both achieving results alongside reduced-calorie diet and increased physical activity. Our free GLP-1 weight loss calculator can help estimate potential weight loss at different doses. A 3-stone loss represents approximately 10–15% of body weight for many adults — well within the range documented in clinical evidence.
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.
Accessing Weight Loss Medication: NHS vs Private
NHS route: Referral to a tier 3 specialist weight management service through your GP. Availability varies by region, and waiting times can be several months. Your GP will assess whether you're eligible.
Private route: Online consultation with a UK-licensed prescriber, prescription issued if clinically appropriate, dispensed by a GPhC-registered pharmacy. Available without NHS referral but involves a consultation fee and medication cost.
Whether choosing NHS or private weight management in the UK, a healthcare professional will assess your individual suitability. Use our free BMI calculator above to check your starting BMI — this is the first step in understanding eligibility. Your GP can discuss both options and help you decide the best path.
- 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.
How much weight is 3 stone in kilograms?
3 stone equals approximately 19 kg (or 19.05 kg exactly). To convert, multiply stone by 6.35029. Using our weight converter, you can instantly switch between kg, stone, and pounds for any weight.
Is 3 stone weight loss considered significant for health?
Yes. Losing just 5–10% of body weight produces measurable health benefits: lower blood pressure, improved blood sugar, reduced joint pain, and decreased cardiovascular risk. A 3-stone loss typically represents 10–15% loss for most adults, placing it well within the significant health-benefit threshold.
How long does it take to lose 3 stone safely?
The NHS recommends losing 0.5–1 kg per week (roughly 0.5–1.5 lbs weekly), which means 3 stone would take approximately 19–38 weeks (4–9 months) through lifestyle changes. Prescription weight loss medication like Mounjaro or Wegovy may accelerate this timeline when combined with diet and exercise.
Will my clothes fit differently after losing 3 stone?
Absolutely. Most people notice clothes becoming visibly looser after 1–2 stone loss. At 3 stone, you'll likely need to replace your wardrobe, and friends and family will almost certainly notice the change in your appearance and how you carry yourself.
Can I lose 3 stone using weight loss injections?
Yes. Clinical trials show GLP-1 and GIP/GLP-1 medications help achieve weight loss in this range when combined with a reduced-calorie diet and physical activity. Try our free GLP-1 weight loss calculator to see projected results. A UK prescriber will assess whether medication is suitable based on your BMI and health.
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.