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 Chewing Gum Help With Weight Loss?
Chewing gum is sometimes promoted as a weight loss aid, but the evidence for significant weight loss is very limited. While chewing gum may have minor effects on appetite or calorie burn, it is not an effective weight management strategy on its own. If you're interested in evidence-based weight loss support in the UK, prescription medications and NHS weight management services offer clinically proven options for eligible adults. This guide explains what's actually 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.
UK-Licensed Prescription Weight Loss Options
If you're looking for effective weight management in the UK, prescription medications are available for adults who meet eligibility criteria. The most commonly prescribed options are:
- Mounjaro (tirzepatide) — a once-weekly GLP-1 and GIP receptor agonist injection that may help reduce appetite and support feeling fuller after smaller meals. Clinical trials showed participants lost an average of 15–21% of their body weight when combined with lifestyle changes.
- Wegovy (semaglutide) — a once-weekly GLP-1 injection with similar mechanisms. Clinical evidence suggests an average weight loss of around 15% of body weight on the maximum dose.
- Saxenda (liraglutide) — a once-daily GLP-1 injection, an older option still available but less commonly prescribed than the once-weekly alternatives.
All three are prescription-only medicines requiring clinical assessment before dispensing. They are not supplements or over-the-counter products — they require a prescription from a licensed healthcare professional. These medications work alongside a reduced-calorie diet and increased physical activity to support sustainable weight loss, and results vary significantly between individuals. Use our free GLP-1 weight loss calculator to explore potential outcomes at different doses.
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.
Who Is Eligible for Prescription Weight Loss Treatment?
Prescription weight loss medications in the UK are available to adults who meet specific criteria:
- BMI of 30 or above (obesity), or
- BMI of 27–29.9 with at least one weight-related health condition — such as type 2 diabetes, prediabetes, high blood pressure, high cholesterol, or sleep apnoea
- For adults of South Asian, Chinese, Black African, or Black Caribbean heritage, lower BMI thresholds may apply (from BMI 27.5 or above) due to higher cardiovascular risk at lower weights.
Use our free BMI calculator to check your personal BMI, then speak to your GP about whether weight management treatment might be suitable for you. NHS eligibility and timelines vary significantly by region — some areas have waiting lists of several months. Private prescription options are also available following an online clinical assessment.
- 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.
Does chewing gum actually help with weight loss?
Evidence suggests chewing gum has only minor effects on weight management. Some studies show it may slightly increase calorie burn or reduce hunger temporarily, but these effects are very small and not sufficient to support meaningful weight loss on their own. Chewing gum is not a weight loss solution.
What prescription weight loss options are available in the UK?
Three GLP-1 medications are licensed for weight management in the UK: Mounjaro (once-weekly), Wegovy (once-weekly), and Saxenda (once-daily). All are prescription-only and require clinical assessment. They may help reduce appetite and support sustainable weight loss when combined with lifestyle changes, though results vary between individuals.
How do I access prescription weight loss medication on the NHS?
Your GP can refer you to a specialist weight management service (tier 3) if you meet eligibility criteria. NHS access depends on your BMI and health conditions, and waiting times vary significantly by region. Speak to your GP to find out what's available in your area and whether you might be eligible.
What's the difference between Mounjaro and Wegovy?
Both are once-weekly injections, but Mounjaro (tirzepatide) is a dual GIP and GLP-1 receptor agonist, while Wegovy (semaglutide) is a GLP-1 agonist only. Clinical trials suggest similar average weight loss outcomes (15–21% for Mounjaro, around 15% for Wegovy), but individual results vary. Your prescriber will advise which might be most suitable for you.
Can I get prescription weight loss injections privately if NHS waiting times are long?
Yes, GLP-1 medications are available privately through GPhC-registered online pharmacies following an online clinical assessment. There is no NHS referral needed. Costs vary by dose and provider, typically ranging from around £129–£320 per month depending on the medication and dose.
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.