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
Losing Weight Shots: Your Full Range of UK Options
Losing weight shots are one option available in the UK for weight management, but they're far from your only choice. Whether you're looking for sustainable weight loss methods or NHS weight loss support, there's a structured pathway designed to help. This guide covers all the options available to you — from free lifestyle support to prescription medications and specialist services — so you can make an informed decision about what's right for your health and circumstances.
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.
Weight Loss Options Available in the UK
The NHS offers a structured approach to weight management across four tiers, and understanding which tier suits you is key to finding the right support.
- Tier 1 (Self-help): Free tools, apps, and online programmes. MyWeightCheck's free BMI calculator and GLP-1 weight loss calculator help you track where you are and what results might be realistic. NHS Weight Loss Plan, apps like OnTrack and Active 10, and community exercise programmes are all available at no cost.
- Tier 2 (Primary care): Your GP can refer you to evidence-based weight loss programmes in your area — often delivered by community services or digital platforms. These typically include behaviour change support and can be highly effective for sustainable weight loss.
- Tier 3 (Specialist services): Multidisciplinary weight management teams offer structured assessment, dietary advice, physical activity support, and prescription medication if appropriate. This is where losing weight shots like Mounjaro and Wegovy are typically prescribed within the NHS.
- Tier 4 (Bariatric surgery): For severe obesity with significant health complications, weight loss surgery may be considered through specialist teams.
- Prescription weight loss medication: Available through both NHS tier 3 services and private prescribing for eligible adults. Options include GLP-1 injections (Wegovy, Saxenda) and the newer dual GIP/GLP-1 injection (Mounjaro).
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.
How to Choose the Right Approach for You
Selecting a weight loss method depends on several factors: your current BMI and health conditions, how much support you need, your lifestyle, and what you can access locally. Start by checking your personal BMI using our free BMI calculator to understand your baseline — this informs which tier of NHS support you're eligible for. Consider whether you prefer self-directed approaches, group support, one-to-one guidance, or medical intervention. If you have weight-related health conditions like type 2 diabetes or high blood pressure, prescription options may be more suitable. Talk to your GP about what's available in your area — waiting lists and local services vary significantly across England, Scotland, Wales, and Northern Ireland. Many people find sustainable weight loss methods combine dietary changes with increased physical activity, and tracking progress using tools like our free progress tracker helps maintain motivation.
- 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 losing weight shots the most effective weight loss option?
Weight loss shots (GLP-1 medications like Wegovy and dual GIP/GLP-1 injections like Mounjaro) are effective for many people, with clinical trials showing average weight loss of 15–21% of body weight. However, effectiveness varies individually, and they work best alongside lifestyle changes. For some people, structured lifestyle support alone is sufficient. There's no single "most effective" option — the best approach is one you can sustain.
What's the difference between NHS and private weight loss shots in the UK?
NHS prescription weight loss injections are available through tier 3 specialist weight management services, often with waiting lists of several months. Private prescribing is faster — available through online consultations with UK-licensed prescribers and GPhC-registered pharmacies — but costs £129–£320+ per month depending on dose. Both routes require clinical assessment; eligibility criteria are similar.
Can I get free weight loss support from the NHS?
Yes. Tier 1 support is completely free — including digital programmes, community services, and exercise classes. Tier 2 (primary care-based) programmes are also free. You only need to pay privately if you access private weight loss medication or private coaching. Your GP can refer you to free tier 1 or 2 support.
How do I know if I'm eligible for losing weight shots on the NHS?
You're typically eligible for NHS prescription weight management if your BMI is 30 or above, or 27–29.9 with weight-related health conditions (type 2 diabetes, high blood pressure, cardiovascular disease, sleep apnoea). For South Asian, Chinese, Black African, or Black Caribbean adults, lower BMI thresholds apply. Your GP can assess eligibility and refer you to specialist services.
What if I want to try lifestyle changes before medication?
That's a sensible approach. Tier 1 and tier 2 NHS support are specifically designed for people wanting to try behaviour change, diet, and exercise first. Many people achieve meaningful weight loss without medication. Our GLP-1 weight loss calculator can help you explore what results might look like with different approaches, and tracking using our progress tracker keeps you accountable and motivated throughout your journey.
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.