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 a Sauna Jacket Help with Weight Loss?
Sauna jackets are marketed as weight loss tools, but the evidence for their effectiveness is limited. While they may cause temporary water weight loss through sweating, they do not burn fat or support meaningful, sustainable weight management. If you're looking for evidence-backed weight loss support in the UK, prescription weight management options and lifestyle changes have stronger scientific backing. This guide explains what sauna jackets actually do and explores more effective alternatives.
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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 Sauna Jackets Work and Why Water Loss Isn't Fat Loss
Sauna jackets are thermal or electrically heated garments designed to increase body temperature and promote sweating. The mechanism behind their marketed weight loss claims is straightforward: sweating causes temporary loss of water weight, which shows on a scale immediately after wearing one.
However, this is not fat loss. Water weight returns within hours of rehydration. Fat loss requires a sustained calorie deficit, where your body burns more energy than you consume. A sauna jacket does not increase your metabolic rate enough to create this deficit in any meaningful way.
- Temporary water loss (returns when you drink water)
- No increase in fat burning
- No metabolic boost
- Risk of dehydration if used excessively
For sustainable weight management in the UK, the NHS recommends combining a reduced-calorie diet with increased physical activity. If you want to check your current weight and BMI context, use our free BMI calculator to understand your baseline health status.
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-Backed Weight Loss Options in the UK
If you're seeking genuine weight loss support, several evidence-backed options are available. Prescription weight loss injections like Mounjaro (tirzepatide) and Wegovy (semaglutide) have strong clinical trial data showing weight loss of 15–21% of body weight when combined with dietary changes and exercise.
Effective weight management combines:
- Calorie deficit through diet (NHS recommends 500 kcal daily deficit for 0.5 kg weekly loss)
- Regular physical activity
- Behavioural support
- Prescription medication if eligible
Our GLP-1 weight loss calculator can help you explore projected weight loss outcomes with evidence-based medication. Your GP can also refer you to NHS tier 3 weight management services to discuss options suited to your health.
- 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 a sauna jacket help me lose weight permanently?
No. Sauna jackets cause temporary water loss that returns when you rehydrate. They do not burn fat or create the calorie deficit needed for lasting weight loss. Sustainable weight management requires dietary changes, exercise, and sometimes prescription support.
Is it safe to use a sauna jacket regularly for weight loss?
Excessive use may cause dehydration, electrolyte imbalance, or overheating. More importantly, it's ineffective for actual fat loss. If you're concerned about weight management, consult your GP about evidence-based approaches rather than relying on sauna jackets.
What does the NHS recommend for weight loss in the UK?
The NHS recommends losing weight at 0.5–1 kg per week through a calorie deficit (typically 500 kcal daily), increased physical activity, and behaviour change support. For eligible adults, referral to specialist weight management services offering prescription medication is also available.
Are weight loss injections like Wegovy more effective than sauna jackets?
Yes, significantly. Clinical trials show Wegovy (semaglutide) helps people lose an average of 15% of body weight alongside diet and exercise. Sauna jackets cause only temporary water loss. Wegovy is prescription-only and requires clinical assessment through your GP or private prescriber.
What is the best way to lose weight sustainably?
Sustainable weight loss combines reduced-calorie diet, regular exercise, behaviour change support, and sometimes prescription medication if eligible. Try our free BMI calculator to understand your health status, and use our weight converter to track progress in familiar UK measurements (stone and pounds).
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.