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 Sauna Help With Weight Loss?
Saunas can help you feel lighter temporarily, but they don't create lasting weight loss on their own. While a sauna session causes your body to lose water through sweating, this weight returns once you rehydrate — making sauna weight loss short-term at best. For genuine, sustainable weight management in the UK, evidence-based approaches combining diet, exercise, and sometimes prescription medication prove far more effective. This guide explains what saunas actually do and explores proven weight loss strategies that work.
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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.
How Saunas Affect Your Body and Weight
When you sit in a sauna, your body temperature rises and you sweat to cool down. This sweating causes water loss, which temporarily reduces the number on the scales — sometimes by 0.5–2 kg in a single session. However, this is not fat loss. Once you drink water and rehydrate, the weight returns within hours. Your body needs this fluid to function properly, so losing it through sweating is neither sustainable nor healthy as a weight loss strategy.
- Saunas increase heart rate and may burn a small number of calories (roughly 40–100 per session depending on temperature and duration)
- Regular sauna use may have modest cardiovascular benefits in some individuals
- Sweating does not burn fat — it is simply water loss
- Dehydration from sauna use is temporary and reverses with fluid intake
For genuine weight loss, you need to create a calorie deficit — meaning you consume fewer calories than your body uses. A sauna session alone cannot achieve this. The NHS recommends losing weight at a rate of 0.5–1 kg per week through sustainable dietary and lifestyle changes.
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.
Proven Weight Loss Strategies That Actually Work
Sustainable weight loss in the UK involves dietary changes, increased physical activity, and sometimes prescription medication. Use our free BMI calculator to check your personal weight status and understand your starting point. The NHS weight management pathway includes tier 1 self-help approaches, tier 2 behaviour change programmes, and tier 3 specialist services for prescription weight loss medication.
- Calorie deficit of roughly 500 kcal per day typically results in ~0.5 kg weekly loss
- Mediterranean and low-carbohydrate diets show strong evidence for sustainable results
- Regular physical activity (150 minutes moderate intensity per week) supports weight loss and health
- Prescription GLP-1 medications (such as Wegovy or Mounjaro) may be prescribed through NHS specialist services or private assessment for eligible adults
Try our GLP-1 weight loss calculator to explore projected outcomes with prescription medication if you're interested in this option.
- 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.
Can you lose weight from sauna use alone?
No. Saunas cause temporary water loss that returns once you rehydrate. Genuine weight loss requires a sustained calorie deficit through diet and activity. Saunas may have cardiovascular benefits when used regularly, but they cannot create the conditions needed for fat loss on their own.
How much weight can you lose in a sauna?
You may lose 0.5–2 kg of water weight during a single session, but this is not fat loss and returns when you drink. To lose actual fat, you need to burn more calories than you consume over weeks and months — a sauna session contributes minimally to this goal.
Is sauna weight loss real or temporary?
It is entirely temporary. Sauna-induced weight loss is pure water loss. Your body requires rehydration, so any weight lost returns within hours. For lasting weight management, evidence supports dietary changes, exercise, and in some cases, prescription medication prescribed by your GP or specialist.
What is the safest way to lose weight in the UK?
The NHS recommends losing 0.5–1 kg per week through a calorie deficit created by eating fewer calories and moving more. Speak to your GP about weight management. For those eligible, prescription weight loss medication may be discussed through specialist NHS services. Calculate your BMI first using our free calculator to understand your starting point.
Are there weight loss injections available in the UK?
Yes. Medications like Wegovy (semaglutide) and Mounjaro (tirzepatide) are UK-licensed for weight management in eligible adults. These require a prescription and clinical assessment. Access is through NHS specialist weight management services or private online prescribing. Results vary individually, and medication is used alongside diet and activity changes.
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.