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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How Much Do Weight Loss Injections 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 online prescribing. Costs vary significantly depending on whether you access them through the NHS, your dose, and your chosen private provider. This guide explains UK pricing, how to access weight loss injections affordably, and what affects the total cost of treatment. Understanding the financial commitment upfront helps you make an informed decision about whether prescription weight loss treatment is right for you.
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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.
Weight Loss Injection Prices — NHS vs Private
NHS access: Weight loss injections on the NHS are free at the point of use, but access is limited to specialist tier 3 and tier 4 weight management services. NHS availability varies significantly by region (Integrated Care Board), and waiting lists can be months or years in many areas. Not all regions currently offer tirzepatide (Mounjaro) on the NHS, though semaglutide (Wegovy) and liraglutide (Saxenda) are more widely available.
Private access pricing (approximate):
- Mounjaro (tirzepatide): £129–£180/month for starting doses (2.5–5mg), rising to £200–£320/month at maintenance doses (10–15mg)
- Wegovy (semaglutide): £160–£250/month depending on dose (0.25–2.4mg)
- Saxenda (liraglutide): £140–£200/month (daily injection, 0.6–3mg)
Prices exclude the cost of the online clinical assessment (typically £30–£75 with private providers). Some private providers offer subscription or discount packages if you commit to longer treatment periods.
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.
Factors That Affect Your Total Cost
Several factors determine your final cost. Treatment duration: Most people use weight loss injections for 6–12 months minimum; some continue longer. Dose escalation: You start on a low dose and increase every 4 weeks, so your monthly cost rises over the first 4–5 months, then stabilises at your maintenance dose. Individual results: If you reach your weight loss goal quickly, you might stop treatment sooner and save money. Health conditions: Some private providers charge differently based on whether you have type 2 diabetes or other weight-related conditions. Calculate your projected costs early using a GLP-1 weight loss calculator, which can estimate both typical weight loss and cumulative medication costs 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.
Is weight loss injection treatment available free on the NHS?
Weight loss injections are available free through NHS specialist weight management services (tier 3/4), but access is very limited and varies by region. Waiting lists can be 6–24+ months. Private access costs £129–£320/month depending on dose and medication. Many people choose private access to avoid NHS waiting lists.
What's included in the monthly cost of weight loss injections?
The monthly cost covers the medication (the injection pen or device) only. It does not include the clinical assessment fee (usually £30–£75 one-time) or follow-up consultations (typically £20–£50 per month with private providers). Some private packages bundle these together.
Does the cost change as my dose increases?
Yes. Starting doses (2.5–0.25mg) are cheapest at approximately £130–£160/month. As you escalate every 4 weeks, costs rise. Maintenance doses (15mg Mounjaro or 2.4mg Wegovy) cost £250–£320/month. Total first-year cost is typically £2,500–£3,500 including assessment and follow-ups.
Can I get weight loss injections cheaper through the NHS?
If you qualify for NHS specialist services in your area, they are completely free. Contact your GP to ask if your region offers tier 3 weight management services and what the waiting list is. NHS access saves the most money but may involve a long wait. Check your local ICB website for current availability.
Are weight loss injections a one-time cost or ongoing?
Weight loss injections are ongoing — you receive a new injection every week. Most people use them for at least 6–12 months, then review with their prescriber. Some continue longer term if they remain effective. You can stop at any time, but weight regain is common if lifestyle changes aren't maintained. Use our free progress tracker to monitor your results and plan your treatment timeline.
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.