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
Does Gluten Free Help With Weight Loss?
Gluten-free diets can support weight loss for some people, but not because gluten itself causes weight gain. The main benefit comes from reduced processed foods, increased awareness of what you're eating, and often choosing whole foods. However, many gluten-free products are high in sugar and fat, which can hinder weight loss. If you're looking for structured weight management support in the UK, prescription options like GLP-1 medications are available for eligible adults. Use our free BMI calculator above to check where you stand, and speak with your GP about what approach suits your health goals.
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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
For adults in the UK with a BMI of 30 or above, or 27–29.9 with weight-related health conditions, prescription weight loss medications are available through the NHS or private prescribing. Three licensed options are currently used for weight management:
- Mounjaro (tirzepatide) — dual GIP and GLP-1 receptor agonist, once-weekly injection, average clinical trial results showed approximately 15–clinically studied weight loss at maximum doses
- Wegovy (semaglutide) — GLP-1 receptor agonist, once-weekly injection, average weight loss around 15% in clinical trials
- Saxenda (liraglutide) — GLP-1 receptor agonist, once-daily injection, approved for longer-term weight management
All three are prescription-only and require a clinical assessment. They work alongside reduced-calorie diets and increased physical activity, not as replacements. Individual results vary significantly. Try our free GLP-1 weight loss calculator to estimate potential results 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.
How to Access Weight Loss Support in the UK
If you're interested in prescription weight loss medication, your first step is a conversation with your GP. They can assess your eligibility based on your BMI, health conditions, and overall health profile. NHS access is through specialist tier 3 weight management services, though waiting times vary by region. Private prescribing is also available through GPhC-registered online pharmacies following an online clinical assessment — this route is often faster but comes at a cost. Either way, a licensed prescriber will determine what's appropriate for you. Whichever path you choose, sustainable weight loss combines medical support with lifestyle changes including balanced eating and regular activity.
- 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 going gluten-free actually cause weight loss?
Not directly. Weight loss from a gluten-free diet typically results from eating fewer processed foods and becoming more mindful about meals, not from eliminating gluten itself. Many gluten-free products are actually high in sugar and fat, which can slow weight loss. The key is overall calorie intake and food quality, regardless of gluten content.
What's the difference between gluten-free diets and prescription weight loss medication?
A gluten-free diet is a dietary approach that works for some people, particularly those with coeliac disease or gluten sensitivity. Prescription weight loss medications like Mounjaro and Wegovy use pharmaceutical mechanisms to reduce appetite and support weight management. They're available on the NHS or privately for eligible adults with a BMI of 30 or above.
Who is eligible for prescription weight loss medication in the UK?
Adults with a BMI of 30 kg/m² or above, or 27–29.9 with at least one weight-related health condition (such as type 2 diabetes, high blood pressure, or sleep apnoea), may be eligible. Your GP or a licensed prescriber can assess your individual situation and determine suitability.
How quickly do prescription weight loss injections work?
Results typically become noticeable within 4–8 weeks as doses increase. Clinical trials show average weight loss of 15–21% body weight over several months, though individual results vary significantly. Weight loss is gradual and sustainable — the NHS recommends losing 0.5–1 kg per week.
Can I combine dietary changes like going gluten-free with prescription weight loss medication?
Yes. In fact, prescription weight loss medications work best alongside lifestyle changes including balanced eating and increased physical activity. Many people find that dietary awareness and medication together provide the strongest results. Speak with your prescriber or GP about creating a comprehensive weight management plan.
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.