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 Do Weight Loss Injections Cost in the UK?
Weight loss injections like Mounjaro and Wegovy vary significantly in price depending on whether you access them through the NHS or privately. Private costs typically range from £129 to £320 per month depending on the dose and provider, whilst NHS access is free at the point of use but involves waiting lists and regional variation. Understanding the true cost of prescription weight loss medication helps you make an informed decision about treatment options in the UK. Our free GLP-1 weight loss calculator can help you explore potential outcomes at different dose levels before committing to treatment.
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.
Private Weight Loss Injection Costs in the UK
Private pricing for weight loss injections varies by dose, brand, and provider. Wegovy (semaglutide) typically costs between £129–£180 per month for lower doses (0.25–1 mg) and £180–£220 for higher doses (1.7–2.4 mg). Mounjaro (tirzepatide) ranges from £150–£200 for starter doses (2.5–5 mg) and £250–£320 for maximum doses (10–15 mg). Saxenda (liraglutide), a daily injection alternative, costs approximately £160–£240 per month. Prices vary between private providers, and many offer discount packages for upfront payment. Each prescription requires an online clinical assessment (typically £20–£50 one-time). Most private providers operate as GPhC-registered online pharmacies and do not require NHS referral—you can access treatment directly. Cost does not include lifestyle support, GP monitoring, or complications if they arise. Always check whether your chosen provider includes follow-up consultations in their pricing.
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 and Costs
Through the NHS, weight loss injections like Mounjaro are free at the point of use if prescribed by a specialist weight management service. However, access is limited: you must be referred by your GP to a tier 3 or tier 4 specialist service, availability varies dramatically by region (ICB), and waiting lists can extend many months or years in some areas. Not all NHS regions currently offer these medications due to cost constraints and capacity. Your GP cannot prescribe weight loss injections directly—only specialist services can. NHS weight management services typically include dietitian support, behaviour change programmes, and GP monitoring as part of the package, which adds value beyond the medication alone. Check your local NHS weight management services' eligibility criteria and current availability before pursuing this route.
- 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 prescription weight loss medication available on the NHS?
Yes, Mounjaro and Wegovy are approved for NHS use through specialist weight management services. However, access requires GP referral and varies by region. Waiting lists can be lengthy, and not all areas currently offer these medications due to budget constraints. Check your local ICB's tier 3/4 weight management services for current availability and eligibility criteria.
Why is private weight loss injection cost so variable?
Costs vary by dose (starter doses cost less than maximum doses), brand (Mounjaro, Wegovy, Saxenda have different pricing), provider, and whether consultations and follow-ups are included. Some providers offer discounts for upfront payment or subscription packages. Always compare the full package, not just the injection cost.
Are weight loss injections worth the cost?
Clinical trials show weight loss injections help an average of 15–clinically studied weight loss alongside diet and exercise. However, individual results vary significantly. Whether the cost is worth it depends on your health goals, ability to sustain lifestyle changes, and whether you qualify for NHS access. Your GP or prescriber can advise on suitability.
Do I need to pay for anything extra alongside the injection cost?
Privately, yes—expect costs for the initial clinical assessment, GP monitoring if required, and potentially dietitian support if purchased separately. NHS provision typically includes these within the specialist service package. Check with your provider what is and isn't included in the quoted price.
Can I use my NHS prescription discount card to reduce weight loss injection costs?
No. Weight loss injections like Mounjaro and Wegovy are not typically covered by standard NHS prescription exemptions or discount schemes when prescribed privately. If prescribed through the NHS, they are free. Private prescriptions must be paid in full through the pharmacy providing them.
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.