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
NHS Weight Loss App Reviews — Which Apps Work Best?
The NHS recommends using digital tools and apps as part of a structured weight management plan. If you're looking to lose weight in the UK, several free and paid apps can support your journey alongside lifestyle changes. This guide reviews the most effective NHS-endorsed weight loss apps, their features, and how they fit into a broader weight management strategy. Whether you're tracking calories, monitoring physical activity, or logging your progress, the right app can make sustainable weight loss more achievable.
10,000+ calculations today · NHS-aligned thresholds · 100% free
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.
Top NHS-Recommended Weight Loss Apps in the UK
The NHS Weight Loss Plan is the official free digital tool developed by the NHS to help UK adults lose weight sustainably. It combines calorie tracking, physical activity logging, and behaviour change support through a smartphone app and website. The app calculates your daily calorie allowance based on your current weight and target, provides meal ideas, and tracks progress over 12 weeks. Other popular NHS-supported options include the Change4Life app, which focuses on family-friendly healthy eating and activity, and Couch to 5K, designed to build fitness gradually. Many apps integrate with wearable devices to track steps and exercise. When choosing an app, look for one that aligns with the NHS recommendation of losing 0.5–1 kg per week for sustainable results. The best app is one you'll use consistently alongside a reduced-calorie diet and increased physical activity. Our free BMI calculator above can help you establish your starting point and set realistic targets before selecting an app.
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.
How Apps Compare: Features and Accessibility
Most NHS weight loss apps are free to download, though some offer premium features for a fee. Free versions typically include basic calorie tracking, food databases, and progress logging. Premium versions may add meal planning, recipes, or one-to-one coach support. The NHS Weight Loss Plan is entirely free and requires no subscription. Accessibility varies — some apps work offline, whilst others require internet connection for food database lookups. For maximum benefit, choose an app that lets you log your weight regularly and view progress trends. Try our free progress tracker on this page to complement any app you choose, and use our weight converter if you need to switch between kg, stone, and pounds.
- 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 the NHS Weight Loss Plan app really free?
Yes, the official NHS Weight Loss Plan is completely free to use. It's available as a web tool and smartphone app (iOS and Android). It includes a personalised calorie allowance, meal suggestions, activity tracking, and a 12-week structured programme with no hidden costs or premium features required.
What's the difference between weight loss apps and prescription weight loss medication?
Weight loss apps are self-directed digital tools that support calorie deficit and lifestyle change. Prescription weight loss medication like Mounjaro or Wegovy is only available through NHS specialist services or private prescribing after clinical assessment. Apps and medication work differently — apps track behaviour, medications help regulate appetite. Many people use both together for best results.
Can weight loss apps help me lose as much weight as GLP-1 injections?
Apps and medication work differently. Digital apps support sustainable weight loss through behaviour change (typically 0.5–1 kg per week). GLP-1 medications like Wegovy may help achieve higher average weight loss (around 15% of body weight in clinical trials) when combined with lifestyle changes. Your GP can advise which approach suits your individual health situation.
Are NHS weight loss apps suitable for people with type 2 diabetes?
Many NHS apps are suitable for people with diabetes, but you should discuss app use with your GP or diabetes team first. Some apps track carbohydrate intake specifically for diabetes management. If you're on insulin or diabetes medication, calorie reduction may require dose adjustments — always consult your healthcare team before starting any weight loss programme.
How do I know if a weight loss app is trustworthy?
Use apps developed or endorsed by the NHS, NICE, or reputable health organisations. Check if the app is certified by recognised standards (look for NHS-endorsed or health data security certification). Avoid apps making unrealistic weight loss promises or guaranteeing specific outcomes. The NHS Weight Loss Plan, Change4Life, and apps developed by established NHS trusts are reliable starting points.
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.