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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Medical Weight Loss Clinic Options in the UK
A medical weight loss clinic in the UK typically offers prescription weight management support alongside lifestyle changes. If you're looking to lose weight, you may be eligible for prescription medications like Mounjaro, Wegovy, or Saxenda through either NHS specialist services or private online prescribing. This guide explains which options are available, how they work, and how to find out if you qualify for weight management uk support. The right approach depends on your health, BMI, and whether you can access NHS services in your area.
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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 Prescription Weight Loss Options
Three GLP-1 and dual-action weight loss medications are currently licensed in the UK for weight management:
- Mounjaro (tirzepatide) — dual GIP and GLP-1 receptor agonist, once-weekly injection. Maximum dose 15 mg. Clinical trials showed average weight loss of 15–21% body weight alongside dietary changes.
- Wegovy (semaglutide) — GLP-1 receptor agonist, once-weekly injection. Maximum dose 2.4 mg. Evidence demonstrates average weight loss around 15% body weight in trials.
- Saxenda (liraglutide) — GLP-1 receptor agonist, once-daily injection. Less commonly prescribed than Mounjaro and Wegovy, but available through specialist services and private prescribers.
All three are prescription-only medicines requiring clinical assessment to determine suitability. Eligibility typically requires a BMI of 30 or above, or BMI 27–29.9 with weight-related health conditions such as type 2 diabetes, high blood pressure, or sleep apnoea. Use our free GLP-1 weight loss calculator to explore potential outcomes at different doses, and our BMI calculator to check where you stand against NHS thresholds.
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.
Accessing Weight Loss Medication: NHS vs Private
NHS access: Available through tier 3 specialist weight management services. You'll need a GP referral, and access varies significantly by region—waiting lists can be lengthy. NICE has approved Mounjaro and Wegovy for NHS use, but availability depends on your local Integrated Care Board.
Private access: Weight loss medication injections uk are available through GPhC-registered online pharmacies following a remote clinical assessment with a UK-licensed prescriber. No referral needed, faster access, but costs range £129–£320+ monthly depending on dose. All prescriptions require a consultation—clinicians assess your medical history, BMI, and suitability before issuing a prescription.
Next step: Speak to your GP about prescription weight loss medication nhs eligibility, or contact a private prescriber. Either way, medications work best alongside a reduced-calorie diet and increased physical activity. Track your progress with our free progress tracker once you begin.
- 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.
Am I eligible for prescription weight loss medication in the UK?
You may be eligible if your BMI is 30 or above, or 27–29.9 with a weight-related health condition (diabetes, high blood pressure, sleep apnoea, etc.). South Asian, Chinese, Black African, and Black Caribbean adults may qualify at lower BMI thresholds. A GP or licensed prescriber will assess your individual circumstances. Use our BMI calculator to check your starting point.
What's the difference between Mounjaro and Wegovy?
Mounjaro (tirzepatide) is a dual GIP and GLP-1 agonist with a maximum dose of 15 mg weekly; Wegovy (semaglutide) is GLP-1 only, maximum 2.4 mg weekly. Clinical trial results show similar average weight loss outcomes (15–21% body weight), though individual results vary. Your prescriber will recommend the most suitable option based on your health profile.
How quickly can I access prescription weight loss medication privately?
Private access is typically faster than NHS. After an online consultation with a licensed UK prescriber, a prescription can be issued within hours to days if approved. Your pharmacy then dispenses the medication. NHS access involves GP referral and specialist assessment, which may take weeks to months depending on your local service waiting lists.
Will my GP prescribe Mounjaro or Wegovy?
Many GPs cannot prescribe these medications in primary care—they're typically initiated through NHS tier 3 specialist weight management services after referral. However, a GP can support your weight loss journey and refer you to appropriate services. Private prescribers (online) can issue prescriptions without NHS referral if you meet clinical criteria.
Can I switch between Mounjaro and Wegovy?
Switching between medications must be managed by your prescriber, not done independently. Approximate dose equivalences exist (e.g., Mounjaro 10 mg ≈ Wegovy 1.7 mg), but there's no official conversion chart. Any change in medication should follow your prescriber's guidance to ensure safe and effective dosing.
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.