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
Affordable Weight Loss Injections in the UK
Weight loss injections (GLP-1 medications like Wegovy and Mounjaro) are available in the UK, but "cheap" options are limited — these are prescription-only medicines requiring clinical assessment. NHS access is available through specialist services but with waiting lists. Private prescriptions typically cost £129–£320 per month depending on the medication and dose. Understanding your options and what affects pricing can help you find the most affordable pathway that suits your health needs and budget.
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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.
How Much Do Weight Loss Injections Cost in the UK?
NHS route: Weight loss injections through the NHS are free once prescribed, but access is limited to specialist tier 3 weight management services. Your GP must refer you, and waiting times vary significantly by region — some areas have waits of 6–24 months. Not all ICBs (Integrated Care Boards) currently offer tirzepatide (Mounjaro) on the NHS, though semaglutide (Wegovy) is more widely available through specialist services.
Private route: Prescriptions through UK-licensed online prescribers typically range from £129–£320 per month, depending on the medication and dose. Wegovy 0.5–1.7 mg usually costs £129–£200/month. Mounjaro 5–15 mg typically ranges from £180–£320/month. Each pen or auto-injector lasts 4 weeks. Additional costs: clinical consultation fees (£20–£50) and GP letters if needed.
- Starting doses are cheaper than maximum doses
- Dose escalation increases monthly costs
- Some providers offer bundle discounts for multiple months
- No NHS prescription charges apply to NHS-prescribed injections
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.
Finding the Most Affordable Option for You
The "cheapest" option depends on your circumstances. If you have a BMI of 30+ or 27+ with weight-related health conditions, ask your GP about NHS specialist referral — there's no cost once approved, though waits can be long. For quicker access, private online prescribing is available without NHS referral. Compare providers carefully: verify they're GPhC-registered pharmacies, check if consultation fees are included in quoted prices, and ask about dose escalation costs before starting.
Use our free GLP-1 weight loss calculator to estimate potential results at different doses, and our BMI calculator to confirm your eligibility. Many people find that the health benefits justify the monthly cost compared to untreated weight-related conditions.
- 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 available on the NHS for free?
Yes, GLP-1 injections (Wegovy, Mounjaro) are available free through NHS specialist weight management services if you meet eligibility criteria. However, access requires GP referral to tier 3 services, and waiting lists can be lengthy — sometimes 6–24 months depending on your region. NHS availability varies significantly across different ICBs.
What's the difference between Wegovy and Mounjaro in terms of cost?
Both are similar in private UK pricing (£129–£320/month). Wegovy (semaglutide) costs roughly £129–£200/month for standard doses. Mounjaro (tirzepatide) typically ranges £180–£320/month because it's a dual-action medication. Your prescriber will assess which is suitable based on your health profile, not just cost.
Can I use Ozempic for weight loss as a cheaper alternative?
Ozempic contains semaglutide but is licensed for type 2 diabetes, not weight loss in the UK. Using it off-label for weight loss is not recommended and may not be covered by private prescribers. Wegovy is the licensed weight management version of semaglutide and is the appropriate choice for weight management.
What happens if I can't afford private weight loss injections?
Explore NHS referral first — it's free once approved. Ask your GP about tier 2 or tier 3 weight management programmes, digital support tools, and behaviour change services. Some weight loss services offer structured payment plans. Our free BMI calculator and weight loss calculator can help you understand your eligibility and options.
Do private weight loss injection costs include GP consultations?
It depends on the provider. Some include an initial online consultation with a UK-licensed prescriber in their quoted price; others charge separately (typically £20–£50). Always clarify total cost before committing. Some providers also charge for follow-up consultations or dose reviews, so ask about the full treatment pathway cost upfront.
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.