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: Prices and NHS Availability in the UK
Weight loss injections are prescription medicines available in the UK through both NHS and private routes, with costs varying significantly depending on your eligibility and access method. If you're considering weight management medication, understanding your options—and what you might pay—is essential. Our GLP-1 weight loss calculator can help you explore potential outcomes, while your GP can assess whether you qualify for NHS-funded treatment or need to pursue private options.
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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.
UK-Licensed Weight Loss Injections and Typical Costs
Three prescription weight loss injections are currently licensed in the UK: Mounjaro (tirzepatide), Wegovy (semaglutide), and Saxenda (liraglutide). Each works through different mechanisms but all are GLP-1 or dual GLP-1/GIP receptor agonists that may help reduce appetite and support weight management when used alongside diet and exercise.
- Mounjaro: Once-weekly injection. Typical private cost: £180–£320 per month depending on dose.
- Wegovy: Once-weekly injection. Typical private cost: £150–£280 per month depending on dose.
- Saxenda: Once-daily injection. Typical private cost: £100–£200 per month.
Prices vary between private providers and may change. NHS costs are covered by the health service if you're eligible and referred to a specialist weight management service—but availability and waiting lists vary considerably by region.
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 vs Private Access: Eligibility and Routes
NHS route: Available through specialist tier 3 weight management services following GP referral. You typically need a BMI of 30 or above, or 27–29.9 with weight-related health conditions like type 2 diabetes or high blood pressure. However, NHS availability is patchy—some regions have significant waiting lists or limited funding. Costs are zero to the patient.
Private route: Access through online prescribing services requires a clinical assessment with a UK-licensed prescriber. You don't need an NHS referral. Private costs range from approximately £129–£320 per month depending on medication and dose, plus initial consultation fees. Start by speaking to your GP about whether you're eligible—this conversation is free and will clarify your options.
- 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.
How much do weight loss injections cost on the NHS?
If you qualify and are referred to an NHS specialist weight management service, the cost to you is free—the NHS covers the medication. However, NHS availability varies significantly by region, and some areas have long waiting lists. Ask your GP whether your local integrated care board funds weight loss medication and what the current waiting time is.
Can I get Mounjaro or Wegovy on the NHS in the UK?
Yes, both Mounjaro and Wegovy can be prescribed through NHS specialist weight management services, but only following referral from your GP and assessment by a tier 3 service. Eligibility requires a BMI of 30 or above (or 27–29.9 with comorbidities). Availability and waiting times vary widely across the UK.
What's the difference between private and NHS weight loss injections?
The medication itself is identical. The main differences are: NHS requires GP referral and specialist assessment (free but may have waiting lists); private requires online clinical assessment (faster but costs £129–£320+ monthly). NHS is free once approved; private you pay per dose. Both require ongoing monitoring.
How long do I need to take weight loss injections?
Treatment duration varies by individual. Clinical trials showed sustained weight loss over 68 weeks. Some people continue longer; others step down once they've reached their goal. Your prescriber will discuss duration as part of your treatment plan. Our progress tracker can help you monitor changes over time.
Am I eligible for weight loss medication on the NHS?
Generally, yes, if you have a BMI of 30+ or 27–29.9 with weight-related health conditions. However, your GP and specialist service will assess you individually based on medical history, other treatments, and local NHS criteria. The only way to find out is to speak to your GP—start that conversation to explore your eligibility and local options.
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.