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
Best Priced Weight Loss Injections in the UK
Weight loss injections are prescription-only medicines that may help support weight management when used alongside diet and exercise. In the UK, GLP-1 medications like Mounjaro and Wegovy are available through NHS specialist services or private prescribing. Costs vary significantly depending on where you access treatment and which medication you're prescribed. Understanding your options — both NHS and private — can help you find the most accessible route for your situation. Our free GLP-1 weight loss calculator can help you explore potential outcomes at different doses.
10,000+ calculations today · NHS-aligned thresholds · 100% free
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 Weight Loss Injection Pricing and Access
Private cost ranges (approximate): Most GPhC-registered UK pharmacies charge between £129 and £320 per month for weight loss injections, depending on the dose and medication. Mounjaro (tirzepatide) and Wegovy (semaglutide) typically fall in this range, with higher doses costing more. Starting doses are usually less expensive than maintenance doses. Some providers offer subscription discounts or reduced pricing for multiple months upfront. NHS access: Weight loss injections are available free through NHS specialist tier 3 weight management services, but eligibility is determined by your GP and availability varies significantly by region. NHS waiting lists can be lengthy — sometimes 6 months to over a year in some areas. Eligibility for both routes: Adults with a BMI of 30 or above (or 27+ with weight-related health conditions like type 2 diabetes or cardiovascular disease) may be eligible. South Asian, Chinese, Black African, and Black Caribbean adults may qualify at lower BMI thresholds due to increased health risk at lower weights.
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.
How to Access Affordable Weight Loss Treatment
The cheapest option is NHS prescription if you can access a specialist service in your area — treatment is free once prescribed. Check NHS weight loss services in your region by asking your GP. If NHS waiting times are prohibitive, private online prescribing offers faster access; compare prices across providers as costs vary. Some people use our free BMI calculator and weight converter to track their starting point and progress. Consider whether the medication cost fits your budget long-term, as most people continue treatment for several months to achieve sustained weight loss. Always ensure any provider is GPhC-registered and that prescribers are UK-licensed healthcare professionals.
- 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.
What's the cheapest weight loss injection in the UK?
NHS prescription is free if you're eligible and can access a specialist service. For private prescribing, prices typically range £129–£320/month depending on dose and medication. Mounjaro and Wegovy have similar cost ranges. Starting doses are generally less expensive than maintenance doses.
Can I get weight loss injections on the NHS?
Yes, through specialist tier 3 weight management services if you meet eligibility criteria (BMI ≥30 or ≥27 with health conditions) and your GP refers you. Availability and waiting times vary by region. Contact your GP to ask about services in your area.
How much does Mounjaro cost privately in the UK?
Private Mounjaro costs typically range from £150–£300/month depending on dose (2.5mg to 15mg). Higher doses cost more. Some pharmacies offer discounts for paying for multiple months upfront. Always check the GPhC registration of the pharmacy.
Is Ozempic the same as Wegovy for weight loss?
Both contain semaglutide, but Ozempic is licensed for type 2 diabetes only — not for weight loss in the UK. Wegovy is the licensed weight management version. Using Ozempic for weight loss would be off-label prescribing and is not recommended.
What should I budget for long-term weight loss injection treatment?
Budget £1,500–£3,800 per year for private treatment at typical doses. Treatment usually continues for 6–12 months or longer depending on your progress. NHS treatment is free if available. Your GP or prescriber can discuss the likely duration needed for your situation.
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.