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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Sauna Jacket Weight Loss: What Works in the UK
Sauna jackets are marketed as a quick weight loss solution, but any weight lost is mainly water and returns when you rehydrate. If you're looking for sustainable weight management in the UK, prescription medications like Mounjaro and Wegovy offer evidence-based alternatives. These GLP-1 and dual GIP/GLP-1 receptor agonists are licensed by the MHRA and available to eligible adults through NHS specialist services or private prescribing. Understanding how genuine weight management works — and what options are available to you — is the first step toward lasting results.
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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-Licensed Prescription Weight Loss Options
If you're interested in weight management uk with proven clinical evidence, three prescription medications are currently licensed in the UK:
- Mounjaro (tirzepatide) — a dual GIP and GLP-1 receptor agonist. In clinical trials, participants lost an average of 15–21% of their body weight over 72 weeks, alongside a reduced-calorie diet and increased physical activity. Doses range from 2.5 mg to 15 mg once weekly.
- Wegovy (semaglutide) — a GLP-1 receptor agonist. Clinical trials showed average weight loss of approximately 15% of body weight at the maximum dose (2.4 mg once weekly).
- Saxenda (liraglutide) — a daily GLP-1 injection, available for adults with a BMI of 30 or above, or 27–29.9 with weight-related health conditions.
All are prescription-only medicines requiring a clinical assessment. Individual results vary significantly, and these medications work best alongside lifestyle changes, not as replacements for them. You can use our free GLP-1 weight loss calculator to explore potential outcomes at different doses.
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 and Eligibility
NHS access: Prescription weight loss medication is available through NHS specialist tier 3 and 4 weight management services. You'll typically need a GP referral, though availability and waiting times vary significantly by region. NICE has approved tirzepatide (Mounjaro) for NHS specialist use, but access depends on your local Integrated Care Board.
Private access: Available through GPhC-registered online pharmacies following an online clinical assessment with a UK-licensed prescriber — no NHS referral needed.
Eligibility: You may be eligible if your BMI is 30 or above, or 27–29.9 with weight-related conditions like type 2 diabetes, high blood pressure, or sleep apnoea. Lower thresholds apply for people of South Asian, Chinese, Black African, or Black Caribbean heritage. Start by discussing your weight management options with your GP, who can assess whether prescription treatment is appropriate for you and explore both NHS and private pathways.
- 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.
Do sauna jackets actually help with weight loss?
Sauna jackets create temporary water weight loss through sweating, but this is regained when you rehydrate. They do not result in genuine fat loss. For sustainable weight management, evidence supports combining lifestyle changes (reduced-calorie diet, physical activity) with prescription medication if clinically appropriate. Our free BMI calculator can help you assess your current health status and discuss options with your GP.
What is the difference between Mounjaro and Wegovy?
Both are once-weekly injections for weight management, but they work differently. Mounjaro (tirzepatide) is a dual GIP and GLP-1 receptor agonist; Wegovy (semaglutide) targets GLP-1 only. Clinical trials showed Mounjaro users lost slightly more weight on average (15–21% vs approximately 15%), but individual results vary. A prescriber will assess which is most suitable for you.
Can I get prescription weight loss medication on the NHS in the UK?
Yes, but access is through specialist tier 3 weight management services, typically via GP referral. Availability varies significantly by region, and waiting lists can be lengthy. Your GP can assess your eligibility and discuss both NHS and private options with you based on your individual circumstances.
What is the safe rate of weight loss with medication?
The NHS recommends losing 0.5–1 kg per week for sustainable results. Prescription weight loss injections typically support this rate alongside a reduced-calorie diet and increased physical activity. Individual results vary based on starting weight, adherence, and lifestyle factors. A prescriber will monitor your progress and adjust your treatment if needed.
How do I find out if I'm eligible for prescription weight loss treatment?
Eligibility depends on your BMI, weight-related health conditions, and ethnicity-adjusted thresholds. Generally, you may qualify with a BMI of 30 or above, or 27–29.9 with conditions like diabetes or high blood pressure. Lower thresholds apply for certain ethnic groups. Contact your GP for a personalised assessment and to explore available options.
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.