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
Low Cost Weight Loss Options in the UK
Losing weight doesn't have to be expensive. In the UK, you have access to free NHS weight loss support, affordable lifestyle changes, and prescription weight management options at various price points. Whether you're looking for budget-friendly approaches or understanding medication costs, this guide covers the most accessible weight loss routes available to UK adults. Your GP can advise on what's available in your area.
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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.
Free and Low-Cost NHS Weight Loss Support
The NHS offers completely free weight loss support through its specialist weight management services. Access begins through your GP, who can refer you to tier 3 or tier 4 services depending on your health needs. These services provide behavioural support, nutrition advice, and monitoring at no cost.
- NHS Weight Loss Plan — free digital tool and support from your GP practice
- Community weight management programmes — free group-based sessions in many areas
- One-to-one GP consultations — free advice on sustainable weight loss and diet changes
- Prescription weight management medication — available through NHS specialist services (eligibility-based, at prescription cost only)
The NHS recommends losing weight at a sustainable rate of 0.5 to 1 kg per week through calorie deficit and increased physical activity. Even a 5% reduction in body weight can bring meaningful health benefits.
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.
Prescription Weight Loss Medication — Costs and Options
Weight loss injections like Mounjaro and Wegovy are available privately in the UK at varying costs depending on dose and provider, typically ranging from £129 to £320 per month. These are prescription-only GLP-1 and dual GIP/GLP-1 receptor agonist medications that may help reduce appetite and support weight management alongside diet and exercise.
Some private providers offer flexible pricing or dose adjustments to reduce costs. Clinical trials showed these medications helped participants lose an average of 15–21% body weight (individual results vary significantly). Check your BMI using our free BMI calculator above to see if you may be eligible. Your prescriber will assess whether medication is suitable for your individual health needs.
For weight management through NHS services, you may eventually access prescription medications if referred to specialist tier 3 services, though availability varies by region and waiting lists can be lengthy. The most cost-effective approach for most people combines free NHS support with consistent lifestyle changes: reducing calorie intake, increasing physical activity, and tracking progress over time.
Use our free weight converter to track your weight in stone and kilograms, and our GLP-1 weight loss calculator to understand potential outcomes with different medication options. Your GP remains the first point of contact for personalised advice on the most affordable and suitable approach for your individual circumstances.
- 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.
What is the cheapest way to lose weight in the UK?
The cheapest option is free NHS support through your GP — including the NHS Weight Loss Plan, community programmes, and dietary advice. These are completely free and evidence-based. Sustainable weight loss through calorie deficit and increased physical activity requires no upfront cost beyond normal food and exercise.
How much do prescription weight loss injections cost in the UK?
Private weight loss injections (Mounjaro and Wegovy) typically cost £129–£320 per month depending on dose and provider. NHS access through specialist services may be free if you're referred and eligible, though availability varies by region. Always confirm exact costs with your prescriber.
Can I get weight loss medication free on the NHS?
Yes, if you're referred to a specialist tier 3 weight management service and meet eligibility criteria (BMI 30+ or 27+ with weight-related health conditions). You pay only the standard prescription cost (£11.90 in England). However, NHS access varies significantly by region and waiting lists can be very long.
What's the fastest low-cost way to lose weight?
A calorie deficit of around 500 kcal per day typically results in approximately 0.5 kg per week loss and is sustainable. The NHS recommends this rate. Faster loss is possible with medical supervision but increases muscle loss risk. Combine dietary changes, increased physical activity, and consistent tracking for best results.
Are there free weight loss apps or tools I can use?
Yes — MyWeightCheck offers free tools including a BMI calculator, weight converter, GLP-1 weight loss calculator, and progress tracker to help you monitor your health metrics and potential outcomes. Many NHS services also provide free digital support and tracking tools through your GP practice.
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.