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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Weight Loss Skin Changes and UK Medication Options
Weight loss can sometimes affect your skin, causing changes in elasticity, texture, or appearance. If you're considering weight management in the UK, prescription medication options are available for eligible adults. This guide explains how gradual weight management affects skin and what prescription weight loss medications you can access through the NHS or private prescribing. Always consult your GP before starting any weight management programme or medication.
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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 Prescription Weight Loss Medications
Three prescription-only weight management medications are currently licensed in the UK: Mounjaro (tirzepatide), Wegovy (semaglutide), and Saxenda (liraglutide). These are GLP-1 receptor agonists (or dual GIP/GLP-1 agonists in the case of Mounjaro) that may help reduce appetite and support gradual weight loss alongside a reduced-calorie diet and increased physical activity.
Eligibility criteria: You may be eligible if you have a BMI of 30 or above, or 27 or above with weight-related health conditions such as type 2 diabetes, high blood pressure, or sleep apnoea. For adults of South Asian, Chinese, Black African, or Black Caribbean heritage, lower BMI thresholds may apply due to increased health risks at lower weights.
Clinical trials showed that individuals taking these medications lost an average of 14–21% of their body weight over 68–72 weeks, though individual results vary significantly. Gradual weight loss tends to be gentler on skin than gradual weight management.
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 Access vs Private Prescription
NHS access: Prescription weight loss medication is available through NHS specialist tier 3 and tier 4 weight management services, following referral from your GP. Availability and waiting times vary considerably by region (ICB). In some areas, waiting lists can be several months to years.
Private access: You can access prescription weight loss medication through GPhC-registered online pharmacies following an online clinical assessment with a UK-licensed prescriber. This route does not require NHS referral and is typically faster, though it involves a cost to you.
In both cases, a prescriber will assess whether weight loss medication is suitable based on your individual health. Use our free BMI calculator to check your BMI, and our GLP-1 weight loss calculator to understand potential outcomes at different medication doses.
- 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 losing weight quickly damage skin?
gradual weight management (more than 1.5kg per week) can sometimes cause loose skin or texture changes because skin elasticity has less time to adapt. The NHS recommends losing 0.5–1kg per week for sustainable results. Gradual weight loss via prescription medication, alongside adequate protein intake and hydration, may minimise skin-related issues.
What skin changes might I experience during weight loss?
Common changes include temporary dryness, improved acne in some individuals, or loose skin folds if weight loss is significant. These usually resolve or improve over months as skin gradually adapts. Staying hydrated, eating adequate protein, and engaging in resistance exercise can support skin health during weight loss.
Can weight loss medication help with skin health?
Prescription medications like Mounjaro and Wegovy support gradual, steady weight loss rather than rapid loss, which may be gentler on skin. However, these medications are primarily for weight management and health conditions, not specifically for skin. Your GP can discuss whether medication is appropriate for your situation.
How do I find out if I'm eligible for prescription weight loss medication?
Your GP can assess your eligibility based on your BMI, health history, and any weight-related conditions. Alternatively, you can use our free BMI calculator on this page to check your BMI against NHS thresholds, then book a GP appointment to discuss your options.
Will the NHS prescribe weight loss medication where I live?
Prescription weight loss medication is available on the NHS through specialist weight management services, but availability varies significantly by region. Your GP can tell you whether your local service offers medication, or you can contact your integrated care board (ICB) to ask about provision in your area.
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.