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
Free tracker included with every download this week
How to Find Weight Loss Support in the UK
If you're searching for weight loss doctors or medical support for weight management, the good news is that the UK has multiple pathways to help. Whether through your NHS GP, specialist weight management services, or private prescribing, you have genuine options. This guide explains how to access professional weight loss support in the UK, what to expect, and how prescription weight loss medications like Wegovy and Mounjaro fit into a comprehensive weight management plan.
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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.
NHS Weight Loss Pathways and Your GP
Your first point of contact for weight loss support in the UK is your GP. GPs can assess your individual health needs, measure your BMI, and discuss lifestyle changes including diet and physical activity. You can use our free BMI calculator to check your starting point before your appointment.
NHS weight management support includes:
- Assessment of your current health and weight-related conditions
- Referral to tier 1 or tier 2 community weight management programmes
- Support for diet and exercise changes
- Referral to specialist tier 3 weight management services if needed
For prescription weight loss medication through the NHS, you'll typically be referred to a specialist weight management service (tier 3). These services assess whether you're eligible based on your BMI and health conditions. Access varies significantly by region and waiting times can be lengthy in some areas.
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.
Private Weight Loss Options and Prescription Medications
If you want faster access to prescription weight loss support, private online prescribing is available through UK-licensed prescribers and GPhC-registered pharmacies. You don't need an NHS referral — you complete an online clinical assessment, and if appropriate, a prescription is issued.
Medications like Wegovy (semaglutide) and Mounjaro (tirzepatide) are available this way. Clinical trials show Wegovy helped participants lose an average of 15% of body weight, whilst Mounjaro demonstrated losses of 15–21% — though individual results vary significantly. Try our free GLP-1 weight loss calculator to estimate potential outcomes at different 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.
Can I get prescription weight loss medication from my NHS GP?
Not directly from your GP in most cases. Prescription weight loss medications are typically prescribed through NHS specialist tier 3 weight management services. You'll need a referral from your GP to access these services, which can involve waiting lists of several months depending on your region.
What's the difference between Wegovy and Ozempic?
Both contain semaglutide, but Wegovy (2.4 mg) is licensed specifically for weight management in the UK. Ozempic (up to 2 mg) is approved for type 2 diabetes. Using Ozempic for weight loss is off-label and not recommended. Always ensure you're prescribed Wegovy for weight loss, not Ozempic.
What BMI do I need to qualify for weight loss medication?
You're typically eligible if you have a BMI of 30 or above, or 27–29.9 with at least one weight-related condition (type 2 diabetes, high blood pressure, sleep apnoea, cardiovascular disease). For South Asian, Chinese, Black African, or Black Caribbean adults, eligibility starts at lower BMI thresholds (27.5+).
How quickly will I lose weight on Wegovy or Mounjaro?
The NHS recommends losing 0.5–1 kg per week for sustainable results. Clinical trials showed average weight losses of 15–21% over several months, but individual results vary significantly. Weight loss depends on the dose, how your body responds, and adherence to reduced-calorie diet and physical activity.
How much does private weight loss medication cost in the UK?
Private Wegovy and Mounjaro costs vary by dose and provider, typically ranging from £129–£320 per month depending on your starting dose and how quickly you increase. Your prescriber can discuss costs and payment options. Always ensure you're using a GPhC-registered pharmacy.
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.