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
Weight Loss Injection Cost in the UK
Weight loss injections in the UK cost between £129 and £320 per month privately, depending on the medication and dose. NHS access is free but typically limited to specialist weight management services with waiting lists. Wegovy (semaglutide) and Mounjaro (tirzepatide) are the main prescription weight management options available. Costs vary significantly based on whether you access treatment through the NHS or privately, and individual prescriber pricing differs. Understanding both options helps you make an informed decision about prescription weight loss medication.
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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 Weight Loss Injection Costs
Private online pharmacies in the UK typically charge between £129 and £320 per month for weight loss injections, though prices vary by provider and dose. Wegovy (semaglutide) at the starting dose of 0.25 mg may cost around £150–£180 per month, while higher doses (up to 2.4 mg) typically range from £250–£320 per month. Mounjaro (tirzepatide) pricing follows a similar pattern, with starting doses around £160–£200 and maximum doses (15 mg) reaching £300–£350 per month.
These are approximate figures — actual costs depend on your chosen provider and the specific dose you're prescribed. Each pen contains four weekly injections, so monthly supply requires one new pen. Private access requires an online clinical assessment with a UK-licensed prescriber before dispensing.
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 Weight Loss Injection Access
NHS access to weight loss injections is free once prescribed, but availability varies significantly by region. Access is through specialist tier 3 weight management services, not standard GP prescription. You'll typically need referral from your GP, and waiting lists can be several months or longer depending on your local integrated care board (ICB). NHS eligibility 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 cardiovascular disease. For South Asian, Black African, Black Caribbean, and Chinese adults, lower BMI thresholds may apply.
Check with your GP about local NHS weight management services, as funding and availability differ across the UK.
- 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.
How much does Wegovy cost privately in the UK?
Wegovy costs approximately £150–£320 per month privately, depending on dose. Starting dose (0.25 mg) is typically £150–£200, while maximum dose (2.4 mg) costs £280–£320. Prices vary between private prescribers and GPhC-registered pharmacies. Each monthly supply is one pre-filled pen containing four weekly injections.
Can I get weight loss injections on the NHS?
Yes, weight loss injections are available on the NHS through specialist tier 3 weight management services. Access is free once prescribed, but requires GP referral and assessment of eligibility. Waiting times vary by region — some areas have months-long waiting lists. Availability depends on your local integrated care board (ICB).
What's the difference between Wegovy and Mounjaro cost?
Costs are similar — both range from approximately £150–£320 per month privately. Mounjaro may be slightly more expensive at higher doses. Wegovy (semaglutide) uses a GLP-1 mechanism, while Mounjaro (tirzepatide) uses dual GIP+GLP-1. Private pricing varies by provider. NHS provides both free if prescribed through specialist services.
Is private weight loss injection treatment worth the cost?
That depends on your circumstances. If NHS waiting times are long in your area, private treatment offers faster access. Use our GLP-1 weight loss calculator to estimate potential results and see whether the investment aligns with your health goals. Always weigh cost against clinical benefit and ensure any prescriber is UK-licensed.
Does the cost include clinical consultations?
Private prescription costs typically include the initial online clinical assessment with a UK-licensed prescriber. However, some providers charge separately for follow-up consultations. Always clarify the full cost before committing. Use our BMI calculator and weight converter to gather your health metrics before your consultation.
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.