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 Injections Cost in the UK
Weight loss injections in the UK range from approximately £129 to £320 per month through private prescribing, depending on the medication and dose. NHS access is available through specialist weight management services but involves waiting lists and regional variation. The main prescription weight loss options are Mounjaro (tirzepatide), Wegovy (semaglutide), and Saxenda (liraglutide). Costs vary based on which medication your prescriber recommends and whether you access treatment privately or through the NHS. Understanding these prices helps you plan your weight loss strategy alongside lifestyle changes.
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 online prescribing is the most accessible route for most UK adults. After an online clinical assessment with a UK-licensed prescriber, prescriptions are dispensed by GPhC-registered pharmacies.
- Wegovy (semaglutide): approximately £129–£250 per month depending on dose (0.25 mg to 2.4 mg)
- Mounjaro (tirzepatide): approximately £150–£320 per month depending on dose (2.5 mg to 15 mg)
- Saxenda (liraglutide): approximately £130–£180 per month (daily injection, 0.6 mg to 3 mg)
Each pen or cartridge typically contains a 4-week supply. Most private providers offer flexible payment options. Prices can vary between providers, so comparing costs across different GPhC-registered pharmacies is recommended. Initial consultations usually cost £20–£50, with repeat consultations at £15–£30.
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 Access and Weight Loss Medication Eligibility
The NHS has approved tirzepatide (Mounjaro) and semaglutide (Wegovy) for specialist weight management services, making them free through NHS prescription once approved. However, NHS access requires referral to a tier 3 or tier 4 specialist weight management service through your GP — you cannot obtain these medications directly from your GP for general weight management.
Eligibility criteria include a BMI of 30 or above, or 27–29.9 with weight-related health conditions such as type 2 diabetes, high blood pressure, or cardiovascular disease. Waiting times vary significantly by region (ICB area), ranging from a few months to over a year in some areas. Use our free GLP-1 weight loss calculator to estimate potential results, and discuss NHS referral options with your GP if you meet the criteria.
- 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?
Yes, Mounjaro (tirzepatide) and Wegovy (semaglutide) are available free through the NHS via specialist tier 3 weight management services. However, access requires GP referral and eligibility assessment. Waiting times vary by region and can be several months to over a year in many areas. Private prescribing offers faster access but costs £129–£320 monthly.
What is the typical cost of Mounjaro in the UK?
Private Mounjaro costs approximately £150–£320 per month depending on the dose (2.5 mg to 15 mg). Each KwikPen contains four weeks' supply. Doses are escalated gradually over weeks, so initial costs may be lower. NHS access is free but requires specialist referral and longer waiting times.
How much does Wegovy cost privately in the UK?
Wegovy typically costs £129–£250 per month through private prescribing, depending on the dose (0.25 mg to 2.4 mg). You progress through five dose levels over approximately 16 weeks. Prices vary between GPhC-registered pharmacies, so it is worth comparing costs. NHS access is free but involves specialist referral and potential waiting lists.
Are there cheaper alternatives to Mounjaro and Wegovy?
Saxenda (liraglutide) is typically cheaper at £130–£180 monthly, though it requires daily injections rather than weekly. All three medications are prescription-only and require clinical assessment. NHS access to any of these medications is free but depends on specialist referral and availability in your region.
Do private weight loss injection costs include the consultation?
Initial online consultations usually cost £20–£50 separately from the medication cost. Repeat consultations typically cost £15–£30. The quoted medication price (£129–£320 monthly) usually covers the prescription only. Some providers bundle consultation and first prescription, so check pricing clearly before proceeding with any provider.
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.