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
Weight Loss for Mums — UK Health Guide
If you're searching for weight loss advice on Mumsnet or similar UK parenting forums, you're not alone — many mums juggle weight management alongside the demands of parenting. This guide covers evidence-based weight management approaches in the UK, from lifestyle changes to prescription options, all based on NHS guidance and clinical evidence. Whether you're looking to lose weight through diet and exercise, or exploring whether prescription weight loss medication might be suitable for you, we'll help you understand your options and what's available on the NHS or privately in the UK.
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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 Loss Methods Available in the UK
Sustainable weight loss in the UK typically starts with lifestyle changes. The NHS recommends losing weight at a rate of 0.5 to 1 kg per week, achieved through a combination of reduced calorie intake and increased physical activity. A calorie deficit of approximately 500 kcal per day supports gradual weight loss without extreme restriction.
- Diet approaches: Mediterranean diet, intermittent fasting (16:8 or 5:2), and low-carbohydrate diets all have clinical evidence supporting modest weight loss
- Physical activity: 150 minutes of moderate activity per week, plus strength training, supports both weight loss and overall health
- Prescription weight management medication: GLP-1 medications like Wegovy (semaglutide) or Mounjaro (tirzepatide) may be prescribed by a GP or specialist for eligible adults with a BMI of 30 or above, or 27–29.9 with weight-related health conditions
For many mums, combining dietary changes with increased movement yields the best sustainable results. Our GLP-1 weight loss calculator can help you explore what prescription medication might achieve alongside lifestyle changes if you're eligible.
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.
Understanding Prescription Weight Loss Options in the UK
If lifestyle changes alone aren't delivering results, prescription weight management medication may be considered. Wegovy (semaglutide) is a once-weekly GLP-1 injection licensed in the UK for weight management in adults with a BMI of 30 or above. In clinical trials, it helped people lose an average of around 15% of their body weight, though individual results vary significantly. Mounjaro (tirzepatide), a dual GIP/GLP-1 medication, is also available and may support weight loss of 15–21% on average in clinical trials. Both are prescription-only and require a clinical assessment before prescribing. You can access these through NHS specialist weight management services (tier 3) or privately via a UK-licensed prescriber following an online consultation. Weight loss medication works best alongside a reduced-calorie diet and increased activity.
Access routes differ: the NHS tier 3 weight management pathway involves referral from your GP but may have significant waiting lists in some areas. Private prescribing offers faster access without an NHS referral but involves a private cost. Whichever route you choose, expect to start on a lower dose and increase gradually over several weeks. Side effects, primarily nausea and digestive changes in the first few weeks, typically improve with time. Our BMI calculator can help you check whether you might meet eligibility criteria, and our weight loss calculator can show projected outcomes at different medication doses to help inform your conversations with a healthcare professional.
- 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 Wegovy available on the NHS for UK mums?
Wegovy can be prescribed through NHS specialist tier 3 weight management services for eligible adults, but availability and waiting times vary significantly by region. Your GP can refer you, but access is not assured. Private prescribing via a UK-licensed prescriber offers faster access without an NHS referral, though this involves a private cost.
What's the difference between Ozempic and Wegovy?
Both contain semaglutide, but Ozempic is licensed for type 2 diabetes (doses up to 2 mg) and is not approved for weight loss in the UK. Wegovy is the licensed weight management version (2.4 mg) and is approved specifically for weight loss. Using Ozempic for weight loss would be off-label.
How much weight can you lose with Wegovy?
In clinical trials (STEP-1), people taking Wegovy 2.4 mg lost an average of approximately 15% of their body weight over 68 weeks, alongside a reduced-calorie diet and increased physical activity. Individual results vary significantly — some lose more, some less. Results are not assured.
Are there side effects with weight loss injections?
Common side effects include nausea, diarrhoea, vomiting, and constipation, particularly in the first few weeks. These usually improve over time as your body adjusts. Less common but serious side effects include severe stomach pain (possible pancreatitis) — seek immediate medical attention if this occurs.
Can I use our tools to check if I'm eligible for weight loss medication?
Our free BMI calculator will show you your BMI and NHS category — this is the first step in eligibility assessment. However, a formal clinical assessment by a GP or licensed prescriber is required to determine actual eligibility and suitability. Use the calculator as a starting point, then discuss options with your healthcare provider.
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.