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
Morning Drink For Weight Loss — What Actually Works in the UK
While popular morning drinks—green tea, lemon water, apple cider vinegar—are often promoted for weight loss, the evidence is limited. For sustainable weight management in the UK, prescription medications like Mounjaro (tirzepatide) and Wegovy (semaglutide) offer clinically-proven support alongside a reduced-calorie diet and increased physical activity. These GLP-1 and GIP/GLP-1 receptor agonist injections are available on the NHS and privately for eligible adults. If you're interested in effective weight management options, it's worth understanding what prescription weight loss medication can actually achieve.
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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 Loss Medications
For adults seeking evidence-based weight management in the UK, prescription medications are available through NHS specialist services and private prescribing. The most widely prescribed options are:
- Mounjaro (tirzepatide) — a once-weekly dual GIP and GLP-1 receptor agonist. Clinical trials showed an average weight loss of 15–21% body weight over 72 weeks, with results varying significantly between individuals.
- Wegovy (semaglutide) — a once-weekly GLP-1 receptor agonist. Clinical evidence indicates an average weight loss of around 15% body weight, again with individual variation.
- Saxenda (liraglutide) — a daily GLP-1 injection, typically resulting in modest weight loss benefits.
Eligibility requires a BMI of 30 or above, or 27–29.9 with weight-related health conditions such as type 2 diabetes, high blood pressure, or sleep apnoea. These medications work by regulating appetite and supporting feeling fuller after smaller meals. Try our free GLP-1 weight loss calculator to explore potential outcomes at different doses.
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 Access Weight Loss Medication in the UK
Access to prescription weight loss medication varies by route. Through the NHS, you'll need a GP referral to a specialist tier 3 or tier 4 weight management service—though waiting lists can be significant in many regions. Alternatively, private online prescribing is available through GPhC-registered pharmacies; you'll complete an online clinical assessment with a UK-licensed prescriber, and if approved, your prescription is dispensed directly.
Your GP can discuss whether prescription weight loss medication is suitable for you based on your individual health circumstances. Use our free BMI calculator to check your starting point, and track your progress with our progress tracker tool once you begin any weight management journey.
- 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 morning drinks like apple cider vinegar effective for weight loss?
Morning drinks have limited evidence for significant weight loss. While some—like green tea—contain compounds with mild metabolic benefits, they don't compare to lifestyle changes or prescription medications. Most claims are overstated. For genuine weight management, focus on calorie deficit, physical activity, and if eligible, discuss prescription options with your GP.
What's the difference between Mounjaro and Wegovy for weight loss?
Both are once-weekly injections for weight management in the UK. Mounjaro (tirzepatide) is a dual GIP/GLP-1 agonist with clinical trial results showing ~15–21% average weight loss. Wegovy (semaglutide) is a GLP-1 agonist with ~15% average weight loss. Individual results vary significantly. Your prescriber will advise which is appropriate for you.
Can I get weight loss medication on the NHS?
Yes. NICE has approved tirzepatide (Mounjaro) and semaglutide (Wegovy) for NHS use through specialist weight management services. You'll need a GP referral. Access varies by region and availability. Private prescribing is also available without NHS referral through GPhC-registered online pharmacies.
What BMI do I need to qualify for prescription weight loss medication?
Generally, a BMI of 30 or above, or 25–29.9 with weight-related health conditions (type 2 diabetes, hypertension, sleep apnoea, cardiovascular disease). Lower thresholds apply for people of South Asian, Chinese, Black African, or Black Caribbean heritage. Check your BMI using our free BMI calculator, then discuss eligibility with your GP.
Is prescription weight loss medication assured to work?
No. While clinical trials show average weight loss of 15–21%, individual results vary. Medications work alongside a reduced-calorie diet and increased physical activity—they're not standalone solutions. A prescriber will assess whether it's suitable for you and monitor your progress. Consistent effort is essential.
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.