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
Achieving 70 Lb Weight Loss: UK Prescription Medication Options
A 70 lb weight loss (approximately 32 kg) is a significant health goal that many UK adults pursue to improve their wellbeing. Prescription weight management medications are now available through the NHS and private prescribers for eligible adults. These medications work alongside dietary changes and physical activity to support sustainable weight loss. Our GLP-1 weight loss calculator can help you estimate potential outcomes with different treatment options, whilst our BMI calculator shows how your current weight relates to health guidelines.
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.
UK-Licensed Weight Loss Medications Explained
Three prescription medications are currently licensed in the UK for weight management: Mounjaro (tirzepatide), a once-weekly injection that activates dual GIP and GLP-1 hormone pathways; Wegovy (semaglutide), a once-weekly GLP-1 injection; and Saxenda (liraglutide), a daily GLP-1 injection. In clinical trials, patients using these medications lost an average of 15–21% of their body weight—though individual results vary significantly. Eligibility typically requires a BMI of 30 or above, or 27 or above with weight-related health conditions such as type 2 diabetes, high blood pressure, or sleep apnoea. All three medications are prescription-only and require a clinical assessment before being prescribed. They work by reducing appetite, helping you feel fuller after smaller meals, and supporting better food choices when combined with lifestyle changes.
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 in the UK
NHS access is available through specialist weight management services (tier 3), though waiting times and regional availability vary significantly. Your GP can refer you to your local service if eligible. Private access is available through GPhC-registered online prescribers following an online consultation—no NHS referral needed. Private treatment typically costs £129–£320 per month depending on medication and dose. Both routes require a prescriber to assess whether medication is suitable for you based on your health history, current medications, and weight loss goals. Whichever route you choose, medication works best alongside a reduced-calorie diet and increased physical activity. Track your progress with our free progress tracker to monitor your weight loss journey over time.
- 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.
Is a 70 lb weight loss realistic with medication?
Clinical trials show average losses of 15–21% of body weight with GLP-1 medications. For someone starting at 220 lbs, this could mean 33–46 lbs. A 70 lb loss is possible but depends on starting weight, adherence, lifestyle changes, and individual response. Your prescriber will discuss realistic targets based on your health.
How long does it take to lose 70 lb on weight loss medication?
Weight loss typically develops over 12–24 months of continued treatment. Most people see meaningful progress within 3–6 months, but sustainable loss continues over longer periods. The NHS recommends losing 0.5–1 kg per week for healthy outcomes. Faster losses are possible but should only occur under medical supervision.
What's the difference between Mounjaro and Wegovy for weight loss?
Both are once-weekly injections, but Mounjaro (tirzepatide) activates two hormone pathways (GIP and GLP-1) while Wegovy (semaglutide) activates one (GLP-1). Clinical trials show Mounjaro achieved slightly higher average weight loss (15–21% vs 15%), though individual results vary. Your prescriber will recommend the most suitable option.
Can I get weight loss medication on the NHS for a 70 lb weight loss goal?
You may be eligible if your BMI is 30 or above, or 27–29.9 with weight-related health conditions. Ask your GP for a referral to your local specialist weight management service (tier 3). NHS availability varies by region, and waiting lists exist in many areas. Private options are available without NHS referral.
What happens after I lose weight—do I stay on medication?
Weight loss medications are typically long-term treatments. If you stop taking them, weight often returns gradually. Your prescriber will discuss how long to continue treatment based on your individual response and health goals. Lifestyle changes remain important throughout and after treatment ends.
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.