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
Online Weight Loss Programs in the UK
Online weight loss programs offer flexible, accessible support for managing your weight from home. In the UK, you can access everything from free NHS resources and digital coaching apps to prescription weight loss medication through online clinics. Whether you're looking for behaviour change support, calorie tracking, or medical interventions, understanding your options helps you choose the right program for your health goals. MyWeightCheck provides free calculators to support your journey alongside whichever program you select.
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.
Types of Online Weight Loss Programs Available in the UK
Online weight loss programs in the UK fall into several categories:
- NHS digital programmes: Free tools like the NHS Weight Loss Plan (formerly Change4Life), available through your GP or directly online, provide behaviour change guidance and calorie tracking support.
- Subscription fitness and nutrition apps: Platforms offering meal planning, exercise routines, and progress tracking (typically £5–£15/month).
- Online coaching services: Virtual consultations with nutritionists or health coaches via video call.
- Prescription weight loss medication: GLP-1 weight loss injections like Wegovy (semaglutide) or Mounjaro (tirzepatide) available through online clinics following clinical assessment — these are prescription-only medicines requiring prescriber approval.
- Hybrid programmes: Combining digital tools with periodic professional support.
Each option varies in cost, time commitment, and level of personalisation. Your GP can advise which tier of support suits your individual needs.
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 Online in the UK
Online prescription weight loss has become increasingly available in the UK through GPhC-registered pharmacies and licensed prescribers. Wegovy (semaglutide) and Mounjaro (tirzepatide) are the main GLP-1 weight loss injections available privately online, both requiring a clinical assessment before prescription. These prescription weight loss medications may help alongside reduced-calorie diet and increased physical activity. NHS weight loss medication is also available through specialist tier 3 services, though access varies significantly by region and waiting times can be lengthy. Our free GLP-1 weight loss calculator can help you estimate potential outcomes at different doses, whilst the BMI calculator lets you track where you sit on the health scale as you progress.
- 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 most effective online weight loss program?
Effectiveness depends on your individual circumstances. Evidence suggests that structured programmes combining dietary change, physical activity, and behaviour support work best. For prescription-eligible adults, GLP-1 medications alongside lifestyle changes show strong clinical trial results. Your GP can help identify which approach suits your health profile, goals, and preferences.
Are online weight loss programs on the NHS free?
Yes. The NHS Weight Loss Plan and referral to tier 1–3 weight management services are free. However, availability varies by region and waiting times can be significant. Private online programmes and prescription medication services typically charge fees ranging from £20–£300+ per month depending on the service.
Can I get Wegovy or Mounjaro through an online clinic in the UK?
Yes. Both Wegovy (semaglutide) and Mounjaro (tirzepatide) are available through private online clinics in the UK following a clinical assessment by a UK-licensed prescriber. These are prescription-only medicines. NHS access is available through specialist weight management services but varies by region. Individual results with GLP-1 medication vary significantly.
Do online weight loss programs work without exercise?
Weight loss is primarily driven by calorie deficit, so diet change alone can produce results. However, physical activity supports muscle retention, cardiovascular health, and long-term sustainability. Evidence-based programmes typically recommend combining dietary change with increased activity for best outcomes. Start with manageable changes and build gradually.
How do I know which online weight loss program is right for me?
Consider your budget, time availability, health conditions, and preferences. Start with a free NHS tool or your GP consultation. If you have a BMI of 30+ or 27+ with weight-related health conditions, discuss prescription options with your GP. Use our free BMI calculator to understand your starting point, and our weight loss calculator to explore what different interventions might achieve.
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.