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
Weekly Weight Loss Tracker: UK Prescription Medication Options
A weekly weight loss tracker helps you monitor progress and stay motivated, especially when taking prescription weight management medication. In the UK, adults eligible for weight loss medication have access to GLP-1 and dual GLP-1/GIP medications through NHS specialist services or private prescribing. Tracking your weekly changes—alongside lifestyle adjustments—provides valuable data to discuss with your GP or prescriber about whether medication is working for you. Our free progress tracker and BMI calculator help you record measurements and assess your health journey throughout your treatment.
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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.
UK-Licensed Prescription Weight Management Options
Three prescription medications are currently licensed in the UK for weight management in eligible adults:
- Mounjaro (tirzepatide) — a dual GIP and GLP-1 receptor agonist injected once weekly. Clinical trials showed participants lost an average of 15–21% of their body weight over 72 weeks, though individual results vary.
- Wegovy (semaglutide) — a GLP-1 receptor agonist injected once weekly. Evidence from clinical trials demonstrated average weight loss of approximately 15% of body weight.
- Saxenda (liraglutide) — a GLP-1 receptor agonist administered as a daily injection. Typically prescribed when other options are unsuitable.
All three are prescription-only medicines requiring clinical assessment by a licensed prescriber. Eligibility includes adults with a BMI of 30 kg/m² or above, or BMI 27–29.9 with weight-related health conditions such as type 2 diabetes, high blood pressure, or sleep apnoea. For adults of South Asian, Chinese, Black African, or Black Caribbean heritage, lower BMI thresholds may apply. Track your BMI using our free BMI calculator to understand your starting point and monitor changes weekly.
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.
Accessing Weight Loss Medication: NHS vs Private Routes
NHS access: NICE has approved tirzepatide and semaglutide for NHS use through specialist tier 3 weight management services. Your GP can refer you to your local service, though waiting times vary significantly by region and availability may be limited. NHS eligibility criteria are strict and access depends on your ICB (integrated care board) commissioning decisions.
Private access: You can access prescription weight loss medication through GPhC-registered online pharmacies following an online clinical assessment with a UK-licensed prescriber—without requiring an NHS referral. Costs typically range from £129–£320 monthly depending on dose and provider. Whichever route you choose, weekly tracking using our free progress tracker helps you and your prescriber assess whether medication is working and whether dose adjustments are needed. Always discuss your weight loss goals and any health concerns with your prescriber before starting treatment.
- 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.
How often should I weigh myself when tracking weekly weight loss?
Weigh yourself once per week on the same day and time for consistency. Early morning, after the toilet and before eating, provides the most accurate measurement. Avoid daily weighing—natural fluctuations in water retention and digestion can cause misleading day-to-day changes. Use our free progress tracker to log weekly measurements and spot trends over 4–8 weeks rather than focusing on single-week changes.
What weight loss rate should I expect on prescription medication?
Safe, sustainable weight loss is typically 0.5–1 kg per week. Prescription GLP-1 medications may support faster initial loss (1–2 kg weekly in some cases), but results vary significantly between individuals. Clinical trials show average losses of 15–21% body weight over several months. Your prescriber will discuss realistic expectations for your situation. Track your actual progress weekly to compare against your personal baseline rather than others' outcomes.
Can I use a weekly weight loss tracker alongside NHS weight management services?
Yes—in fact, keeping a weekly log is encouraged by NHS specialists. Recording your weight, diet, activity, and any side effects helps your healthcare team assess medication effectiveness and make informed decisions about dose adjustments. Many NHS tier 3 services ask patients to track progress between appointments. Our free progress tracker integrates with your BMI calculator results for a complete health picture.
Is it normal for weight loss to slow down after a few weeks on medication?
Yes, this is very common. Initial rapid loss often includes water weight and may slow after 4–8 weeks as your body adapts. Continuing to track weekly helps you distinguish between natural plateaus and genuine stalling. If your prescriber increased your dose recently, allow 4 weeks to assess the full effect. Discuss any concerns about slowing loss with your GP—dose adjustments or additional lifestyle changes may be needed.
What should I do if my weekly weight loss tracker shows no progress for several weeks?
First, ensure you're tracking consistently—same day, same time each week. One or two weeks without change is normal; concern is warranted if there's no loss over 4–6 weeks despite taking medication as prescribed. Discuss this with your prescriber; they may adjust your dose, review your diet and exercise, or investigate other factors. Combining medication with a calorie deficit (around 500 kcal below your needs) and physical activity typically produces the best results.
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.