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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Face Slimming After Weight Loss: UK Prescription Options
Facial fat loss is often one of the most visible results of successful weight management, and prescription weight loss medication may help achieve this. If you're eligible, UK-licensed options like Mounjaro and Wegovy can support sustainable weight reduction when combined with lifestyle changes. This guide explains how prescription weight management works in the UK, who is eligible, and how to explore your options through the NHS or private prescribing. Use our free GLP-1 weight loss calculator above to see projected results, and our BMI calculator to check where you currently stand.
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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 Weight Loss Medications
Three prescription-only medications are licensed for weight management in the UK: Mounjaro (tirzepatide), a dual GIP and GLP-1 receptor agonist that acts on two appetite-regulating pathways; Wegovy (semaglutide), a once-weekly GLP-1 injection; and Saxenda (liraglutide), a daily injection. Clinical trial data shows Mounjaro helped participants lose an average of 15–21% of their body weight, while Wegovy showed similar results around 15% body weight reduction — though individual results vary significantly.
You may be eligible if you have a BMI of 30 or above, or a BMI of 27–29.9 with weight-related health conditions such as type 2 diabetes, high blood pressure, or cardiovascular disease. For adults of South Asian, Chinese, Black African, or Black Caribbean heritage, lower BMI thresholds may apply. Eligibility is always assessed individually by a prescriber following a clinical consultation.
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 in the UK
NHS access: Weight loss medication is available through specialist tier 3 or tier 4 weight management services, typically accessed via GP referral. However, NHS availability varies significantly by region, and waiting lists can be lengthy.
Private access: UK-licensed prescribers can assess and prescribe following an online consultation through GPhC-registered pharmacies, without needing an NHS referral. This route is often faster, though costs typically range from £129–£320 per month depending on dose. Either way, medication works best alongside reduced-calorie diet and increased physical activity — it supports weight loss, not replaces healthy habits.
- 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 weight loss medication help reduce facial fat specifically?
Weight loss from any source — including prescription medication — draws from fat stores across the entire body, including the face. Facial fat reduction is often among the first visible changes during weight loss. However, genetics influence where your body loses fat first, so results vary between individuals.
How long does it take to see face slimming results?
Most people begin noticing visible weight loss changes within 4–8 weeks on prescription medication, though facial changes may take longer to become obvious. Clinical trials typically measured results over 12–16 weeks. Consistency with medication and lifestyle changes matters more than speed.
What's the difference between Mounjaro and Wegovy?
Both are prescription-only once-weekly injections. Mounjaro uses a dual mechanism (GIP + GLP-1), while Wegovy uses GLP-1 only. Clinical trial data suggests Mounjaro may support slightly greater average weight loss, though both medications work effectively. Your prescriber will determine which is more appropriate for you.
Can I get weight loss medication through my NHS GP?
Most prescription weight loss medication in the UK is initiated through specialist weight management services, not standard GP practices. Ask your GP about referral to local tier 3 services. If waiting times are long, private prescribing offers a faster alternative with GPhC-registered providers.
Do I need to diet and exercise alongside medication?
Yes. Clinical trials showed medication works best with a reduced-calorie diet and regular physical activity. Medication helps regulate appetite and supports feeling fuller, but it's not a replacement for healthy eating and exercise habits. This combination approach gives the best, most sustainable results.
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.