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
What Are Slimming Drops? UK Health Information
Slimming drops are not a standard weight management treatment in the UK health system. The term "slimming drops" often refers to unregulated products with unclear ingredients, or sometimes colloquially to injectable weight loss medications like semaglutide (Wegovy). If you're exploring weight management options, prescription medications available through the NHS or private prescribers are clinically tested and regulated. Our free BMI calculator can help you assess your current health status, whilst our GLP-1 weight loss calculator can show projected outcomes with evidence-based medication.
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.
Understanding Weight Loss Options in the UK
Prescription weight loss medications are the regulated, evidence-based options available in the UK. These include semaglutide (Wegovy) — a once-weekly injectable GLP-1 receptor agonist — and tirzepatide (Mounjaro), approved for adults with a BMI of 30 or above, or 27 or above with weight-related health conditions. These are prescription-only medicines requiring clinical assessment.
Unregulated "slimming drops" sold online typically lack safety data and clinical testing. The NHS recommends caution with unproven weight loss products. Licensed prescription medications have undergone rigorous clinical trials showing they may help participants lose an average of 14–21% of body weight when combined with lifestyle changes — though individual results vary significantly.
- Prescription medications are regulated by the MHRA
- Clinical trials support their safety profile
- Results are achieved alongside diet and physical activity changes
- Access available through NHS or private prescribers
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 Safe Weight Management Treatment
In the UK, weight management treatment is available through two routes. NHS access requires referral to a specialist tier 3 weight management service through your GP — availability varies by region and waiting lists can be lengthy. Private access is through GPhC-registered online prescribers following a clinical assessment; prescription and cost vary by provider and medication dose.
Whatever route you choose, genuine weight management requires a clinical assessment to check eligibility and suitability. Use our free weight converter to understand your current weight in kg, stone, and lbs, and our BMI calculator to see where you sit on NHS health thresholds. This information is helpful to discuss with your GP or prescriber.
- 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 slimming drops effective?
Most unregulated slimming drops lack clinical evidence. Prescription weight loss medications (like Wegovy) have clinical trial data showing average weight loss of 14–21% of body weight. Individual results vary. Always choose evidence-based, prescription options assessed by a licensed healthcare professional rather than unregulated products.
Are slimming drops safe?
Unregulated slimming drops may contain undisclosed ingredients and carry unknown safety risks. Licensed prescription medications are regulated by the MHRA and have undergone rigorous safety testing. Any medication should only be used following a clinical assessment from a qualified prescriber.
What's the difference between slimming drops and Wegovy?
"Slimming drops" is an informal term for various unregulated products. Wegovy (semaglutide) is a prescription-only, NHS-regulated injectable medication with clinical trial evidence supporting its effectiveness. Wegovy requires a prescription and clinical assessment — it is not available as drops.
Can I get slimming drops on the NHS?
The NHS does not prescribe unregulated slimming drops. Weight management on the NHS is through specialist services prescribing evidence-based medications like semaglutide (Wegovy) or tirzepatide (Mounjaro) following clinical assessment and eligibility checks.
What should I do if I want help with weight loss?
Speak to your GP about accessing NHS tier 3 weight management services, or explore private prescribing through a GPhC-registered provider. Both routes require clinical assessment. Use our free BMI calculator to understand your current health status before your appointment.
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.