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 Due To Stress — UK Medication Options
Stress can trigger significant weight loss through elevated cortisol levels, reduced appetite, and increased metabolism. If you've experienced unintended weight loss due to stress, prescription weight management medications are available in the UK to help stabilise your weight and support overall health. This guide explores your options, eligibility criteria, and how to access treatment through the NHS or private prescribing.
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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 for Weight Management
Three prescription-only weight management medications are currently licensed in the UK for adults with excess weight:
- Mounjaro (tirzepatide) — a once-weekly injection that activates dual GIP and GLP-1 hormone pathways. Clinical trials showed participants lost an average of 15–21% of their body weight alongside diet and exercise changes.
- Wegovy (semaglutide) — a once-weekly GLP-1 injection. In trials, average weight loss was approximately 15% of body weight over 68 weeks.
- Saxenda (liraglutide) — a once-daily GLP-1 injection offering a daily alternative to weekly options.
All three medications may help regulate appetite, reduce food cravings, and support sustainable weight management. Individual results vary significantly, and medication works most effectively alongside a reduced-calorie diet and increased physical activity. You can calculate your potential weight loss using our free GLP-1 weight loss calculator to understand realistic expectations for your situation.
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 How to Get Started
NHS access: Referral to a specialist tier 3 weight management service through your GP is the NHS route. Eligibility requires a BMI of 30 or above, or 27–29.9 with weight-related health conditions such as type 2 diabetes, high blood pressure, or sleep apnoea. However, NHS waiting lists vary by region and can be lengthy.
Private access: GPhC-registered online pharmacies offer prescription weight loss medication following a clinical assessment with a UK-licensed prescriber. This route doesn't require an NHS referral and is accessible without waiting lists, though costs apply.
Next step: Speak with your GP about your weight and stress-related concerns. They can assess your eligibility and discuss the best option — NHS referral, private prescribing, or lifestyle-focused support — for your individual circumstances. Use our free BMI calculator to check your current BMI before your appointment.
- 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.
Can stress-related weight loss be a UK pharmacy with prescription medication?
Yes. If you've lost weight due to stress and your GP assesses you as eligible (based on BMI and health conditions), prescription weight loss medications like Mounjaro or Wegovy may be appropriate. These support sustainable weight management but work best alongside stress management strategies and lifestyle changes. Always discuss your specific situation with your GP.
What is the difference between Mounjaro and Wegovy for weight management?
Mounjaro is a dual GIP and GLP-1 receptor agonist; Wegovy is a GLP-1 agonist only. Mounjaro users showed slightly higher average weight loss in trials (15–21% vs 15%), but both are effective. Choice depends on your medical history, injection preference (weekly vs daily), and your prescriber's recommendation.
How quickly can I get prescription weight loss medication on the NHS?
NHS timelines vary significantly by region. Some specialist services have waiting lists of several months. Your GP can refer you to your local tier 3 weight management service for assessment. Private online prescribing offers faster access but involves private costs ranging from £129–£320 monthly depending on dose and provider.
Am I eligible for prescription weight loss treatment in the UK?
You may be eligible if you have a BMI of 30 or above, or 27–29.9 with at least one weight-related health condition (type 2 diabetes, high blood pressure, sleep apnoea, cardiovascular disease, or dyslipidaemia). Your GP or a licensed prescriber will assess your individual circumstances. Use our free BMI calculator to check your starting point.
What should I discuss with my GP about stress-related weight loss?
Tell your GP about the timing and severity of your weight loss, any stress triggers, current symptoms, medical history, and previous weight. Ask about eligibility for prescription weight loss medication, referral to specialist services, and whether stress management support (counselling, CBT) might help alongside medication. Bring your BMI information to discuss treatment 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.