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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Can Prescription Weight Loss Medication Help with Loose Skin?
Loose skin after significant weight loss is a common concern for many people in the UK. While prescription weight management medications like Mounjaro and Wegovy can support sustainable weight loss, the rate and approach to losing weight matters for skin health. Slower, gradual weight loss alongside strength training and proper nutrition may help your skin adapt better than rapid weight reduction. Understanding your options for prescription weight loss in the UK can help you make informed decisions about the pace and method that suits your body best.
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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 Options and Skin Health
Three prescription weight loss medications are currently licensed in the UK: Mounjaro (tirzepatide), Wegovy (semaglutide), and Saxenda (liraglutide). These GLP-1 and GIP/GLP-1 receptor agonist medications may support weight loss alongside reduced-calorie diet and increased physical activity. However, they work differently in terms of pace—Mounjaro and Wegovy are once-weekly injections, whilst Saxenda is a daily injection.
The rate of weight loss can affect skin elasticity. Clinical trials show that participants on these medications lose an average of 14–21% of body weight over several months, which is gradual enough to allow some skin adaptation. Crucially, combining any weight loss approach with strength training and adequate protein intake may help preserve muscle mass and support skin firmness during weight loss. Our free GLP-1 weight loss calculator can help you estimate potential weight loss timelines at different doses, giving you a clearer picture of the pace involved.
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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.
Getting Prescription Weight Loss Treatment in the UK
To access prescription weight loss medication in the UK, you'll need eligibility assessment. Adults with a BMI of 30 or above, or 27–29.9 with weight-related health conditions, may qualify. NHS access is through specialist tier 3 weight management services (referral from your GP), though regional availability varies significantly and waiting lists can be lengthy.
Private online prescribing is also available through GPhC-registered pharmacies following a clinical assessment—no NHS referral needed. Your prescriber will consider your full health picture, including skin concerns. Remember that prescription medication works best alongside lifestyle changes: structured exercise, adequate hydration, and protein intake all support both sustainable weight loss and skin health. Check your personal BMI using our free BMI calculator to understand where you stand currently.
- 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 prescription weight loss medication cause loose skin?
Not directly. The medications themselves don't cause loose skin—gradual weight management from any source can lead to loose skin if collagen and elastin can't adapt quickly enough. However, gradual weight loss (0.5–1 kg per week), which is typical with GLP-1 medications, gives skin more time to adjust. Combining weight loss with strength training and adequate protein helps preserve muscle and supports skin elasticity.
Can I use Mounjaro or Wegovy and still have tight skin after weight loss?
Yes, potentially. The pace of weight loss with these medications is moderate enough to allow skin adaptation in many cases. Individual results vary depending on age, genetics, skin elasticity, and lifestyle factors. Strength training during weight loss is particularly important for maintaining muscle tone and supporting skin appearance. Your prescriber can discuss realistic expectations for your situation.
What's the best weight loss rate for skin health?
The NHS recommends losing 0.5–1 kg per week for sustainable results and to allow skin adaptation. gradual weight management (more than 1.5 kg per week) is more likely to result in loose skin. GLP-1 medications typically support this moderate pace when used alongside a reduced-calorie diet and exercise, rather than extreme restriction.
Does the NHS help with loose skin after weight loss?
The NHS can refer you to dermatology or plastic surgery for significant loose skin concerns, though this is typically after weight has stabilised. Tier 3 specialist weight management services may offer guidance on skin health during the weight loss process itself. Ask your GP about what support is available in your area.
How do I find out if I'm eligible for prescription weight loss medication?
Contact your GP for an initial assessment. They'll check your BMI and health history to determine if referral to specialist services is appropriate. Alternatively, use our free BMI calculator above to see where you currently stand against NHS eligibility thresholds. Private prescribing options are also available if you prefer to explore those first.
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.