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 in the UK are available through both NHS and private routes, with costs varying significantly depending on the medication, dose, and how you access treatment. If you're considering prescription weight loss medication like Mounjaro or Wegovy, understanding the true cost — including the injection itself, clinical assessments, and ongoing support — is essential. This guide breaks down what you'll actually pay and what's included in the price across both NHS and private access routes.
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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 Costs: NHS vs Private
Private cost range: Weight loss injections typically cost between £129 and £320 per month in the UK through private online prescribing services, depending on the medication and dose. Mounjaro and Wegovy (the two most common brands) sit at the higher end of this range.
- Mounjaro (tirzepatide): Usually £180–£300/month, depending on dose (2.5mg through 15mg)
- Wegovy (semaglutide): Typically £150–£250/month, depending on dose (0.25mg through 2.4mg)
- Saxenda (liraglutide): Daily injection alternative, often £120–£180/month
NHS access: Free on prescription if approved by your specialist weight management service. However, NHS availability is extremely limited — waiting lists in many areas can be months to years, and access varies significantly by region (Integrated Care Board). Your GP can refer you to tier 3 specialist services, but there is no assures of approval or short waiting times.
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.
What's Included in the Private Cost?
When you pay for weight loss injections privately, your cost typically includes: the prescription fee (often £15–£30), the clinical assessment by a UK-licensed prescriber, the medication itself (per KwikPen or auto-injector), and ongoing support or monitoring. Some providers include follow-up consultations; others charge separately. Always check what's included before purchasing. Use our free GLP-1 weight loss calculator to explore projected results at different doses, and our BMI calculator to assess whether you may be eligible for treatment. Many people find it helpful to calculate their starting BMI and projected healthy weight range using these tools before booking a consultation.
- 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.
Are weight loss injections free on the NHS in the UK?
They can be, but only if prescribed through NHS specialist weight management services (tier 3 or 4). Access is extremely limited and varies by region — waiting lists are often very long (months to years in many areas). Your GP can refer you, but approval and availability are not assured.
What's the typical cost of Mounjaro in the UK?
Private Mounjaro typically costs £180–£300 per month, depending on the dose you're on. Costs increase slightly as you increase doses from 2.5mg to 15mg. Each pen contains 4 weekly doses (one month's supply). Prices vary between providers.
Is there a cheaper alternative to Mounjaro or Wegovy?
Saxenda (liraglutide) may be slightly cheaper at £120–£180/month, but it's a daily injection rather than weekly. Results in clinical trials were slightly lower than Mounjaro/Wegovy. All three are prescription-only and require clinical assessment — cost should not be the only factor.
Do I need to pay for ongoing GP appointments if taking weight loss injections privately?
Not necessarily. Private prescribing providers typically manage your prescription, but GP support is optional. Some people have regular GP check-ups for safety monitoring (not required but recommended). Your GP cannot prescribe these medications — only specialists or private prescribers can.
What factors affect the total cost of weight loss injections?
Total cost depends on: initial clinical assessment fee, the dose you're prescribed, how quickly you titrate (increase doses), whether you need follow-up consultations, and how long you stay on the medication. Most people need 12+ weeks at therapeutic doses to see meaningful results, making long-term cost substantial.
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.