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 Much Does The Weight Loss Injection Cost In The UK?
Weight loss injections (GLP-1 medications like Mounjaro and Wegovy) are available in the UK through both NHS specialist services and private prescribing routes, with costs varying significantly. Private prescriptions typically cost between £129 and £320 per month depending on the medication, dose, and provider, whilst NHS access is free but availability depends on your region and specialist service waiting lists. Understanding the full cost picture — including consultation fees, medication price, and ongoing monitoring — helps you make an informed decision about which route suits your circumstances.
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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.
Private vs NHS Costs: What You'll Actually Pay
Private weight loss injection costs in the UK:
- Mounjaro (tirzepatide): £129–£280 per month depending on dose (2.5mg to 15mg). Each KwikPen contains 4 weekly doses. Starting doses cost less; maximum doses cost more.
- Wegovy (semaglutide): £140–£320 per month depending on dose (0.25mg to 2.4mg). Doses escalate over 16 weeks, so costs typically rise as you progress through the titration schedule.
- Saxenda (liraglutide): £150–£300 per month. A daily injection (not weekly), so slightly different cost structure.
- Online consultation fee: £10–£50 (one-off or per consultation, varies by provider).
- NHS route: Free medication once prescribed through tier 3 specialist weight management services, but may involve lengthy waiting lists (weeks to years depending on your region).
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.
Hidden Costs and Budget Planning
Beyond the monthly injection cost, factor in ongoing GP or prescriber reviews (private consultations typically £20–£50 every 3–4 months), potential blood tests if you have diabetes or other health conditions, and lifestyle support (dietitian appointments, gym membership). Most private providers include one or two follow-up consultations in their initial fee. If you're accessing through the NHS, there are no direct medication costs, but waiting times can be months long. Use our free GLP-1 weight loss calculator to estimate your likely dose and project costs over a full treatment cycle. Calculate your healthy weight range using our BMI calculator to understand your personal weight loss target and how long treatment might take.
- 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.
Is weight loss injection treatment expensive?
Private costs range from £129–£320/month depending on medication and dose, plus one-off consultation fees of £10–£50. NHS access is free once prescribed through specialist services, but waiting lists can be lengthy (weeks to years). Costs depend on your starting dose and how quickly you escalate.
Do private online prescriptions include follow-up consultations?
Most private providers include 1–2 follow-up consultations within their service fee. Additional consultations beyond this typically cost £20–£50 each and are needed every 3–4 months. Always check the provider's full terms before purchasing.
Can I get weight loss injections free on the NHS?
Yes, if prescribed through tier 3 NHS specialist weight management services. However, access varies by region and waiting lists can be very long (sometimes 18+ months). Your GP can refer you to your local specialist service to check eligibility and waiting times.
How do I budget for a full year of weight loss injection treatment?
Private costs typically total £1,500–£3,200 for a year (including consultations), as doses increase over the first 16 weeks. Total cost depends on which medication you take and your final maintenance dose. Our GLP-1 calculator can help estimate your likely dose and projected timeline.
Are there any additional costs I should know about?
Yes — regular GP or prescriber reviews (£20–£50 every 3–4 months), potential blood tests if you have diabetes, and optional support services like dietitian appointments or lifestyle coaching. Some private providers offer these as add-ons. Budget £50–£100/month for comprehensive support beyond medication alone.
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.