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
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Best Free Weight Loss Apps in the UK
If you're looking to lose weight in the UK, free weight loss apps can be a practical starting point for tracking calories, exercise, and progress. Many apps integrate with NHS weight management guidance, helping you build sustainable habits without cost. Combined with realistic goals and consistent effort, apps work best alongside other weight management strategies — whether that's lifestyle changes, increased physical activity, or in some cases, prescription support from your GP. Here's what you need to know about the most effective free options available.
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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.
Top Free Weight Loss Apps Available in the UK
Several free weight loss apps are widely used across the UK for calorie tracking and fitness monitoring:
- MyFitnessPal — tracks calories, macro nutrients, and exercise; large food database with UK brands and portion sizes.
- Lose It! — simple calorie counter with barcode scanning and meal logging; free version covers daily tracking.
- Cronometer — detailed nutrition tracking; useful if you have specific dietary needs or health conditions.
- Strong — focuses on exercise and strength training logging; pairs well with diet tracking apps.
- NHS Weight Loss Plan — free NHS-endorsed 12-week programme combining app-based tracking with motivational content.
The NHS Weight Loss Plan is particularly valuable for UK users as it aligns with official NHS weight management guidance and requires no subscription. Most free versions have limitations — premium tiers unlock additional features — but the free tiers cover the essentials: calorie counting, food logging, and progress tracking.
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.
Combining Apps With Wider Weight Management Strategy
Free apps alone rarely produce significant weight loss without complementary lifestyle changes. For sustainable weight management in the UK, apps work best alongside:
- Consistent calorie deficit (typically 500 kcal/day for ~0.5 kg per week loss)
- Regular physical activity — even 30 minutes most days makes a difference
- Professional GP support — especially if you have underlying health conditions
- NHS tier 1 or tier 2 weight management services where available in your area
If you have a BMI over 30 or weight-related health conditions, your GP may refer you to specialist weight loss medication NHS services or prescription options. Use our free BMI calculator above to check your personal BMI and understand what support tier you may qualify for. Apps complement these interventions but should not replace professional guidance.
- 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.
Are free weight loss apps effective on their own?
Free weight loss apps are helpful tracking tools but work best combined with dietary changes and physical activity. They provide accountability and visibility into calorie intake, which supports behaviour change. However, apps alone typically don't produce significant weight loss without a calorie deficit and lifestyle commitment. The most effective approach combines app tracking with realistic goals and sustained effort.
Which NHS weight loss apps are recommended in the UK?
The NHS Weight Loss Plan is the official NHS-endorsed free 12-week programme available on iOS and Android. It combines app tracking with motivational content aligned to NHS guidelines. MyFitnessPal, Lose It!, and Cronometer are also popular and track against NHS recommendations. Always check that any app you choose displays UK portion sizes and includes common UK food brands for accurate logging.
Can free weight loss apps track macro nutrients?
Most free apps include macro tracking — MyFitnessPal, Cronometer, and Lose It! all show protein, carbohydrates, and fat breakdowns in their free versions. This is useful if you're following specific diet approaches or have nutritional targets set by a GP. The free versions usually cover daily macro tracking; premium versions may add more detailed analysis and custom goal setting.
Should I use a free weight loss app if I'm on prescription weight loss medication?
Yes — a free weight loss app can complement prescription weight management medication by tracking intake and progress. If you're using GLP-1 medication (such as Mounjaro or Wegovy), logging your food helps monitor portion sizes and identify trigger foods. Always discuss your app use with your prescriber or GP, especially if medication affects your appetite — app data can inform your treatment plan.
What if I'm not seeing results with a free weight loss app?
If results plateau after consistent use, consider: checking whether you're in a genuine calorie deficit, increasing physical activity intensity, reviewing food logging accuracy, and speaking to your GP about underlying factors (thyroid, medications, metabolic conditions). Your GP can refer you to tier 2 or tier 3 NHS weight management services, or assess whether prescription weight loss support is appropriate for your situation.
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.