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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Body Dysmorphia After Weight Loss: Understanding the Psychological Impact
Body dysmorphia after weight loss — sometimes called "invisible weight loss" or body image disturbance — is a genuine psychological experience where people struggle to see or accept their changed body, even after significant weight loss. After achieving meaningful weight management through lifestyle changes or medication, some people find themselves unable to recognise their new appearance or continue to feel discomfort with how they look. This guide explores what causes this, how it differs from other body concerns, and what support is available in the UK.
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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.
Weight Management Options and Body Image
If you're considering weight management in the UK, whether through lifestyle changes, nhs weight loss services, or prescription weight loss medication like Mounjaro, Wegovy, or Saxenda, it's worth understanding the full picture of what weight loss involves — including potential psychological effects.
- Mounjaro (tirzepatide) — a dual GIP/GLP-1 receptor agonist injection licensed for UK adults with a BMI of 30+ or 27+ with weight-related health conditions. Clinical trials showed average weight loss of 15–21% of body weight over 72 weeks.
- Wegovy (semaglutide) — a GLP-1 receptor agonist, once-weekly injection. Average weight loss approximately 15% of body weight in clinical trials.
- Saxenda (liraglutide) — a daily GLP-1 injection option, offering sustainable weight loss for eligible adults.
All three are prescription-only and require a clinical assessment. Weight loss injections in the UK are typically offered through NHS specialist tier 3 weight management services or via private online prescribing following an online consultation with a licensed prescriber.
Clinically BackedWeight Loss
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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.
NHS Access, Support, and Next Steps
If you're struggling with body image after weight loss medication or lifestyle-based lose weight efforts, mental health support is as important as physical health. The NHS offers free talking therapies through your GP, including cognitive behavioural therapy (CBT), which is evidence-based for body dysmorphia and body image concerns.
- Speak to your GP about how you're feeling — body image concerns after weight loss are recognised and treatable.
- Ask about NHS weight loss medication nhs options or referral to a tier 3 specialist weight management service if you haven't already been assessed.
- Request a mental health referral if you're experiencing persistent body dysmorphia — don't wait until it affects your wellbeing.
- Use our free BMI weight loss calculator and progress tracker to keep a clear, factual record of your health journey — sometimes seeing objective health gains (like improved BMI, lower blood pressure) helps reframe body perception.
- 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.
What's the difference between body dysmorphia and normal concern about appearance after weight loss?
Normal post-weight-loss concern is temporary and manageable. Body dysmorphia involves persistent, distressing preoccupation with perceived flaws in appearance that are not observable to others, or appear minor. It causes significant distress, impacts daily life, and doesn't improve even when appearance objectively changes. If this describes you, speak to your GP.
Can weight loss medication like Mounjaro or Wegovy trigger body dysmorphia?
gradual weight management — whether from medication or lifestyle changes — can sometimes create a psychological mismatch between your self-image and your new body. This is not inevitable, but awareness is important. Combining weight management with mental health support reduces risk. Always discuss any concerns with your prescriber and GP.
Is body dysmorphia after weight loss treatable?
Yes. Cognitive behavioural therapy (CBT) and other evidence-based therapies are effective for body dysmorphia. The NHS offers free talking therapies through your GP. Treatment success is high when individuals seek help early. You don't have to manage this alone.
Should I stop weight loss medication if I develop body dysmorphia concerns?
Do not stop medication without speaking to your prescriber. Instead, contact your GP or prescriber to discuss how you're feeling. Mental health support and medication adjustment can happen simultaneously. Your prescriber needs to know about psychological effects so they can help manage both your physical and mental health.
How do I access NHS weight loss services and mental health support together?
Ask your GP for a referral to your local tier 3 specialist weight management service — they assess whole-person health, including mental wellbeing. You can also request mental health support (talking therapies) from your GP independently. Both services are free on the NHS and can work together to support your overall health.
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.