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
Weight Loss Tips For UK Adults — What Works
If you're looking for weight loss tips that actually work, you're in the right place. Weight loss is a complex health goal influenced by diet, exercise, genetics, and sometimes medical factors. The good news is that the NHS and private healthcare in the UK now offer more options than ever — from lifestyle support to prescription weight loss injections like Mounjaro and Wegovy. This guide covers evidence-based strategies, UK-licensed medications, and how to find out if prescription weight loss is right for you.
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 — What Are Your Options?
For adults struggling with weight management, prescription weight loss medications have transformed what's possible in the UK. The three main options currently available are:
- Mounjaro (tirzepatide) — a once-weekly injection that activates two hormone pathways (GIP and GLP-1). Clinical trials showed participants lost an average of 15–21% of body weight over 72 weeks when used alongside a reduced-calorie diet and increased physical activity.
- Wegovy (semaglutide) — a once-weekly GLP-1 receptor agonist injection with an average weight loss of around 15% body weight in clinical trials.
- Saxenda (liraglutide) — a once-daily GLP-1 injection approved for weight management in the UK.
All three are prescription-only medicines requiring a clinical assessment. You can calculate your personal BMI and explore estimated weight loss projections using our free tools above to help guide your conversation with a healthcare professional about whether prescription weight loss medication might be suitable for you.
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.
Who Is Eligible for Prescription Weight Loss Medication in the UK?
Not everyone needs or will benefit from prescription weight loss medication. The NHS recommends prescription options for adults with a BMI of 30 or above, or a BMI of 27–29.9 with at least one weight-related health condition such as type 2 diabetes, high blood pressure, or sleep apnoea. South Asian, Chinese, Black African, and Black Caribbean adults may be eligible at lower BMI thresholds (from 27.5) due to higher health risks at lower weights.
Access varies: the NHS offers medications through specialist tier 3 weight management services (waiting lists apply), while private online prescribing is also available. Your GP can assess your individual eligibility or you can request an online consultation with a UK-licensed prescriber. Whatever route you choose, sustainable weight loss works best when medication is combined with dietary changes and increased physical activity — use our free progress tracker to monitor your 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.
What are the most effective weight loss tips for UK adults?
Evidence-based tips include creating a calorie deficit of 500 kcal per day for gradual weight loss of 0.5–1kg weekly, increasing protein intake to preserve muscle, staying hydrated, and combining diet with regular physical activity. NHS weight management UK services also recommend behaviour change support. For those eligible, prescription medications like Mounjaro or Wegovy can complement these lifestyle changes — ask your GP about what might suit your situation.
How much weight can you lose with GLP-1 weight loss injections?
In clinical trials, GLP-1 medications like Wegovy showed average weight loss of around 15% of body weight, while dual-action medications like Mounjaro showed 15–21% average weight loss. These results were achieved alongside a reduced-calorie diet and increased physical activity. Individual results vary significantly — some people lose more, others less. A prescriber will discuss realistic expectations with you during your clinical assessment.
What's the difference between NHS and private weight loss medication access in the UK?
NHS prescription weight loss medication is available through specialist tier 3 weight management services (requires GP referral and may involve waiting lists). Private options are available through GPhC-registered online pharmacies following an online clinical assessment — faster access but at personal cost. Both require a valid prescription from a UK-licensed prescriber and individual eligibility assessment.
Can you lose weight without medication in the UK?
Yes — many people achieve sustainable weight loss through lifestyle changes alone: consistent calorie deficit, balanced nutrition, regular physical activity, and behaviour change support. The NHS offers free weight management programmes including digital tools and community support. However, if you've tried lifestyle changes and struggled, prescription medication may be worth discussing with your GP, particularly if you have a BMI over 30 or weight-related health conditions.
How do I know if weight loss medication is right for me?
The first step is to check your BMI using our free BMI calculator above. If your BMI is 30 or above (or 27+ with health conditions), speak to your GP about specialist weight management services or ask about private prescribing options. A licensed prescriber will assess your medical history, current medications, and weight loss goals to determine if Mounjaro, Wegovy, Saxenda, or another approach is appropriate for you.
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.