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
Do Sauna Suits Help You Lose Weight?
Sauna suits are marketed as quick weight loss tools, but the reality is more complex. While they may cause rapid water loss through sweating, this is temporary and not the same as losing fat. If you're looking for sustainable weight management in the UK, evidence-based approaches — including lifestyle changes and, where appropriate, prescription weight loss medication — are far more effective. Understanding how sauna suits actually work is the first step to choosing strategies that truly support your health.
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.
How Sauna Suits Work and Why Water Loss Isn't Fat Loss
Sauna suits (also called sweat suits or sauna jackets) trap body heat and increase perspiration. When you wear one during exercise, you may lose several kilograms of weight within hours — but this is almost entirely water loss, not fat loss. Your body needs water to function, so this weight returns as soon as you rehydrate, typically within 24 hours.
Why this matters: Losing water weight does not reduce your actual body fat percentage or improve your health markers like blood sugar or cholesterol. The NHS recommends sustainable weight management that includes reduced-calorie eating and increased physical activity, not rapid dehydration methods.
Using sauna suits can also pose health risks. Excessive sweating without adequate hydration can lead to heat exhaustion, dehydration, electrolyte imbalance, and in extreme cases, heatstroke. This is especially risky for people with cardiovascular conditions or diabetes.
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.
Evidence-Based Weight Loss That Actually Works
For genuine, lasting weight loss, NHS guidance recommends losing 0.5 to 1 kg per week through a calorie deficit and increased physical activity. You can calculate your personal BMI using our free BMI calculator above to understand your starting point, then work towards a healthy weight range for your height.
For some adults with a BMI of 30 or above — or 27 or above with weight-related health conditions — prescription weight loss medication may be appropriate. Options available in the UK include GLP-1 injections like Wegovy, which work alongside diet and exercise. Try our free GLP-1 weight loss calculator to estimate potential results with evidence-based treatment.
Always consult your GP about the right approach for your individual health 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.
Will I lose fat weight in a sauna suit?
No. Sauna suits cause water loss through sweating, not fat loss. The weight you lose returns within 24 hours once you drink fluids. Fat loss requires a sustained calorie deficit over weeks and months, not rapid dehydration.
Are sauna suits safe for weight loss?
They carry health risks including dehydration, heat exhaustion, and electrolyte imbalance. They are not recommended by the NHS for weight management and can be dangerous for people with heart conditions, diabetes, or other health issues. Consult your GP before using one.
What's the difference between water weight and fat loss?
Water weight is temporary fluid loss that returns within hours of rehydrating. Fat loss is permanent reduction in body fat, achieved through calorie deficit and physical activity over time. Only fat loss improves your health markers and BMI.
What does the NHS recommend for weight loss?
The NHS recommends losing 0.5 to 1 kg per week through a calorie deficit (around 500 kcal/day) combined with increased physical activity. For eligible adults, prescription weight loss medication can support these lifestyle changes.
Can I use a sauna suit with weight loss medication like Wegovy?
While sauna suits won't interfere with medications, they're not necessary and carry risks. Evidence-based weight loss medication works through hormonal mechanisms — not dehydration. Focus on proper hydration, diet, exercise, and medical guidance instead.
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.