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 Warm Water Help With Weight Loss?
Warm water alone won't cause weight loss, but it may support your efforts when combined with other healthy habits. Many people wonder if drinking warm water has special weight loss benefits compared to other fluids. The science shows the picture is more nuanced — whilst hydration is important for weight management, warm water itself doesn't trigger fat burning or significantly speed up metabolism. However, staying well-hydrated can help regulate appetite and support your body's natural functions. If you're interested in evidence-based weight management, check your BMI first using our free BMI calculator to understand your current health position.
10,000+ calculations today · NHS-aligned thresholds · 100% free
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.
What Does the Science Say About Warm Water and Weight Loss?
Research into warm water and weight loss shows modest effects at best. Some studies suggest that drinking water — whether warm or cold — before meals may slightly reduce appetite and support eating less, but this effect is small. Drinking water raises your metabolic rate temporarily (called thermogenesis), burning approximately 4–5 extra calories per 500ml of water consumed. This is minimal compared to the 500–1000 kcal daily deficit needed for effective weight loss.
The NHS emphasises that effective weight management requires a calorie deficit alongside physical activity and healthy eating. Warm water can help with hydration, which supports metabolism and appetite regulation, but it's not a weight loss tool in itself. Cold water and room temperature water provide identical benefits. The temperature doesn't matter — what matters is staying consistently hydrated throughout the day.
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.
Effective Weight Loss Strategies That Actually Work
For genuine, sustainable weight loss, focus on evidence-based approaches: creating a calorie deficit of around 500 kcal daily for approximately 0.5 kg weight loss per week; increasing physical activity; eating protein-rich whole foods; and reducing processed foods and sugary drinks. The NHS recommends combining dietary changes with increased activity for the best results.
For adults with a BMI of 30 or above, or BMI 27–29 with weight-related health conditions like type 2 diabetes or high blood pressure, prescription weight loss medication may be appropriate. GLP-1 weight loss injections like Mounjaro and Wegovy work through a different mechanism — they help reduce appetite and support feeling fuller — and are used alongside lifestyle changes. Our free GLP-1 weight loss calculator can help you explore what results might be possible with medical support.
- 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 drinking warm water boost metabolism?
Warm water provides a very small temporary boost to metabolism (thermogenesis) of about 4–5 calories per 500ml, regardless of temperature. This is too minimal to support meaningful weight loss on its own. Effective weight loss requires a significant calorie deficit through diet and activity.
Is warm water better than cold water for weight loss?
No. Research shows cold and warm water have identical effects on metabolism and appetite. What matters is consistent hydration throughout the day. Drink whichever temperature you prefer and will consume regularly.
Can warm water help reduce appetite?
Drinking any water — warm or cold — before meals may cause slight appetite reduction by filling your stomach. However, this effect is modest. For more significant appetite support, speak to your GP about whether prescription weight loss medication might be suitable for you.
What's the most effective way to lose weight?
The NHS recommends creating a calorie deficit (approximately 500 kcal daily) through reduced-calorie eating and increased physical activity, aiming for 0.5–1 kg weight loss per week. Staying hydrated supports this process, but hydration alone won't cause weight loss without dietary changes.
Should I use warm water instead of other weight loss methods?
No. Warm water should be part of overall healthy habits, not a replacement for proven methods. Combine hydration with a balanced diet, physical activity, and for some people, prescription weight loss treatment. Use our free BMI calculator to assess whether you might be eligible for medical weight management support.
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.