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
Can You support gradual weight management? What the NHS Says
Losing 10kg in one month is significantly faster than NHS weight loss guidance recommends — which suggests a safe rate of 0.5 to 1kg per week. While gradual weight management is possible, especially with medical support, it carries risks including muscle loss, nutrient deficiencies, and potential metabolic changes. This guide explains what realistic weight loss looks like, how prescription weight management in the UK works, and when to seek professional help if you're aiming for rapid results.
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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.
Why 10kg in One Month Is Faster Than Recommended
The NHS recommends losing 0.5 to 1kg per week for sustainable, healthy weight loss. This equals roughly 2 to 4kg per month. Losing 10kg in a month would require losing approximately 2.3kg weekly — more than double the NHS safe rate.
At this pace, your body is forced into an extreme calorie deficit, typically requiring a reduction of around 2,300 calories per day (beyond normal metabolic needs). This level of deficit often results in:
- Muscle loss — your body breaks down lean tissue for energy, not just fat
- Nutritional deficiencies — essential vitamins and minerals are often insufficient
- Metabolic slowdown — your resting metabolic rate decreases, making future weight loss harder
- Fatigue and weakness — energy depletion can affect daily functioning
- Hair loss and skin changes — common side effects of gradual weight management
Use our free BMI calculator above to establish your starting point and healthy weight range — this helps create a realistic, sustainable plan with your GP.
Clinically BackedWeight Loss
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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.
Medical Weight Loss Options If Rapid Loss Is Medically Necessary
If your GP has advised gradual weight management due to significant health risks (such as severe obesity complications), prescription weight loss medication may be considered as part of a medically supervised programme. In the UK, prescription weight management options include GLP-1 receptor agonist injections like semaglutide (Wegovy) or tirzepatide (Mounjaro), which may support weight loss through appetite regulation alongside reduced-calorie diet and physical activity.
Clinical trials show average weight loss of 14–21% of body weight over several months — not one month. Any gradual weight management programme should include regular monitoring by your GP or a specialist weight management service. Try our GLP-1 weight loss calculator to estimate potential results with medical support, or speak to your GP about NHS tier 3 specialist weight management services available in your area.
- 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.
Is losing 10kg in one month possible?
Technically possible but not safe without intensive medical supervision. It would require an extreme calorie deficit (approximately 2,300+ calories per day), which risks muscle loss, nutrient deficiencies, metabolic damage, and fatigue. The NHS recommends much slower rates.
What's a realistic weight loss rate according to the NHS?
The NHS recommends losing 0.5 to 1kg per week, which equals 2 to 4kg per month. This rate allows your body to lose mostly fat while preserving muscle, maintaining energy, and supporting sustainable habit change.
Could prescription weight loss injections help achieve gradual weight management?
GLP-1 medications like Wegovy may support weight loss of 14–21% over several months alongside reduced-calorie diet and exercise. They're not designed for one-month results and require clinical assessment. Your GP can discuss whether prescription weight management is appropriate for you.
What should I do if my GP has advised gradual weight management?
If gradual weight management is medically necessary due to serious health complications, ask your GP for referral to a tier 3 specialist weight management service. They can provide supervised, medically safe gradual weight management programmes with regular monitoring and nutritional support.
Why does gradual weight management often lead to weight regain?
Extreme dieting slows metabolism, depletes muscle, creates intense hunger, and is unsustainable. When normal eating resumes, the slower metabolism makes regaining weight likely. Slow, steady weight loss with lifestyle changes produces better long-term results.
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.