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 Aids — What Works in the UK?
Weight loss aids include a range of prescription medications, lifestyle programmes, and support tools designed to help you lose weight alongside diet and exercise. In the UK, options range from NHS-supported programmes to prescription weight management injections. This guide covers the main evidence-based weight loss aids available, how they work, and how to access them through the NHS or private prescribing. Check your BMI using our free calculator above to understand your starting point.
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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.
Prescription Weight Loss Medications Available in the UK
Several prescription-only weight loss medications are licensed in the UK for managing excess weight. GLP-1 receptor agonists — such as semaglutide (Wegovy) and tirzepatide (Mounjaro) — are the most commonly prescribed. These work by activating natural hormone pathways that help regulate appetite and support feeling fuller after meals. Mounjaro is a dual GIP and GLP-1 agonist, whilst Wegovy is a GLP-1 agonist alone. In clinical trials, these weight loss injections helped adults lose an average of 15–21% of their body weight when combined with diet and exercise changes. Another option is liraglutide (Saxenda), a daily GLP-1 injection. All three are prescription-only and require a clinical assessment before prescribing. Try our free GLP-1 weight loss calculator above to explore potential outcomes at different doses.
- Mounjaro: doses up to 15 mg once weekly
- Wegovy: doses up to 2.4 mg once weekly
- Saxenda: doses up to 3 mg once daily
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.
NHS Weight Management Pathways and Lifestyle Support
The NHS offers a structured approach to weight management uk through its four-tier pathway. Tier 1 includes self-help tools and community programmes; Tier 2 offers primary care-based support from your GP; Tier 3 provides specialist multidisciplinary weight management services where prescription medications may be offered; Tier 4 covers bariatric surgery for severe obesity. Access to prescription weight loss medication nhs is typically through Tier 3 specialist services, though availability and waiting times vary significantly by region. The NHS Weight Loss Plan and community-based programmes like the Change4Life scheme offer evidence-based lifestyle support. You can use our free BMI calculator to check your starting point and determine which tier might be most appropriate for your situation.
- 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.
What are the most effective weight loss aids available in the UK?
Prescription GLP-1 and GLP-1/GIP medications (Mounjaro, Wegovy, Saxenda) are evidence-based aids licensed for weight management. Clinical trials show average weight loss of 15–21% body weight when combined with diet and exercise. Non-prescription aids include NHS-backed programmes, calorie-counting apps, and fitness tracking tools. Individual effectiveness varies — your GP can assess which option suits you.
Can I get weight loss injections on the NHS?
Yes, prescription weight loss medication nhs is available through specialist Tier 3 weight management services. You typically need a GP referral and a BMI of 30 or above, or 27 or above with weight-related health conditions. Waiting times vary by region — some areas have long lists. Private prescribing is faster if you choose to pay privately following a clinical assessment.
What's the difference between Mounjaro and Wegovy?
Wegovy (semaglutide) is a GLP-1 agonist activating one hormone pathway; Mounjaro (tirzepatide) is a dual GIP and GLP-1 agonist, activating two pathways. Clinical trials show Mounjaro resulted in slightly higher average weight loss (15–21% vs 15% for Wegovy), though individual results vary. Both are once-weekly injections and require prescription.
How quickly can I expect to lose weight with these aids?
Safe weight loss is typically 0.5–1 kg per week. With GLP-1 medications alongside lifestyle changes, users in clinical trials lost significant weight over 68–72 weeks. Individual results vary based on starting weight, dose, diet adherence, and exercise. Use our GLP-1 weight loss calculator to estimate potential outcomes at different doses.
Are there non-prescription weight loss aids I can access right now?
Yes. Free NHS resources include the NHS Weight Loss Plan, community weight management programmes, and digital tools. MyWeightCheck's free BMI calculator, weight converter, and progress tracker help you track your health journey. Calorie-counting apps, fitness trackers, and diet support apps are widely available. Always discuss major lifestyle changes with your GP first.
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.