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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Weight Loss and Reflux: Managing Both Together in the UK
If you're managing acid reflux whilst trying to lose weight, you may feel caught between two competing health challenges. The good news is that moderate weight loss can actually improve reflux symptoms in many people, and there are prescription weight management options available in the UK that may help. This guide explains how weight loss affects reflux, which medications are available, and how to access them through the NHS or privately.
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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 Prescription Weight Loss Options for Reflux Management
Three prescription-only weight management medications are currently licensed in the UK and may be suitable for eligible adults managing reflux alongside excess weight:
- Mounjaro (tirzepatide) — dual GIP and GLP-1 receptor agonist, 2.5 mg to 15 mg once weekly. Clinical trials showed average weight loss of 15–21% body weight over 72 weeks alongside dietary changes.
- Wegovy (semaglutide) — GLP-1 receptor agonist, 0.25 mg to 2.4 mg once weekly. STEP-1 trial data showed approximately 15% average body weight loss at the maximum dose.
- Saxenda (liraglutide) — GLP-1 receptor agonist, 0.6 mg to 3 mg once daily.
All three require a prescription following clinical assessment. Eligibility in the UK typically includes adults with a BMI of 30 or above, or 27 or above with weight-related health conditions. Individual results vary significantly. Calculate your personal BMI using our free BMI calculator above to check where you fall within NHS guidelines, then discuss with your GP whether prescription weight loss medication may be appropriate for your situation.
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 vs Private Access — How to Get Started
NHS route: Request a GP referral to your local tier 3 specialist weight management service. NHS provision varies significantly by region (ICB), and waiting lists can be lengthy in many areas. Once referred, a specialist team will assess whether prescription medication is suitable, considering your reflux and other health factors.
Private route: Online consultations with UK-licensed prescribers are available without NHS referral. A qualified prescriber will review your medical history, including reflux management, and issue a prescription if clinically appropriate. Private medication costs range from approximately £129–£320 per month depending on dose and provider. Either way, weight loss of even 5–10% of your body weight may help reduce reflux severity whilst improving overall health. Track your progress with our free progress tracker as you work towards your goals.
- 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 losing weight actually help with reflux?
Yes, moderate weight loss often improves acid reflux symptoms. Excess weight increases pressure on the stomach and weakens the lower oesophageal sphincter. The NHS and clinical evidence both support weight loss as part of reflux management. Even 5–10% weight reduction can make a measurable difference. Your GP can discuss whether weight loss medication is appropriate alongside your current reflux treatment.
Can I take weight loss injections if I have reflux or GERD?
Weight loss injections like Mounjaro and Wegovy are generally safe for people with reflux, though side effects like nausea and indigestion may temporarily worsen symptoms in some people. A prescriber will assess your individual situation, including your reflux history and medications. Never start any new medication without informing your healthcare provider about your reflux condition.
How do I know if I'm eligible for prescription weight loss medication on the NHS?
You're typically eligible if you have a BMI of 30 or above, or 27 or above with weight-related health conditions (which may include reflux complications). However, NHS provision and waiting lists vary by region. Book an appointment with your GP to discuss your weight management goals and ask about referral to specialist services. They can advise on local availability and timescales.
What's the difference between NHS and private weight loss medication?
Both routes use the same licensed medications (Mounjaro, Wegovy, Saxenda), but access differs. NHS requires a GP referral and specialist assessment, often with waiting lists. Private consultations are faster and don't require NHS referral, but medication costs are out-of-pocket (typically £129–£320/month). Both require a valid prescription from a UK-licensed prescriber. Ask your GP which option suits your situation.
How much weight can I expect to lose with prescription weight loss medication?
Clinical trials showed average weight loss of 15–21% body weight with Mounjaro and approximately 15% with Wegovy over several months, alongside a reduced-calorie diet and increased physical activity. However, individual results vary significantly — some people lose less, some more. Your prescriber cannot assures specific outcomes. Use our free GLP-1 weight loss calculator to explore estimated projections based on clinical data, then discuss realistic goals with your healthcare provider.
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.