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
Over the Counter Weight Loss Pills in the UK
If you're searching for over the counter weight loss pills in the UK, it's important to understand what's actually available without prescription and what alternatives might be more effective. The reality is that truly effective weight loss medications in the UK require a prescription from a healthcare professional. However, there are several OTC supplements, dietary approaches, and prescription options to explore depending on your individual health needs and BMI. Understanding your options — and your current BMI — is the first step toward sustainable weight management.
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.
What Over the Counter Weight Loss Options Exist in the UK?
The truth about over the counter weight loss pills in the UK is straightforward: there are very few genuinely effective OTC weight loss medicines available. Most supermarket and health shop weight loss supplements contain ingredients like caffeine, green tea extract, or glucomannan (a soluble fibre), which may offer modest support for weight management but lack the clinical evidence of prescription medications.
- Orlistat (Xenical) — Available OTC at lower doses (60mg) from pharmacies without prescription, though 120mg requires a prescription. It reduces fat absorption in the digestive system.
- Caffeine and herbal supplements — Green tea, conjugated linoleic acid (CLA), and other natural extracts have limited evidence for weight loss.
- Fibre supplements — Glucomannan and psyllium husk may help with satiety but are not weight loss medicines.
For more effective weight management, prescription medications and NHS weight loss programmes often provide better results. Use our free BMI calculator to understand whether prescription weight loss treatment 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.
Prescription Weight Loss Medications — More Effective Options
If you're looking for genuine results, prescription weight loss injections are typically far more effective than OTC pills. In the UK, licensed prescription weight loss medications include Wegovy (semaglutide), Mounjaro (tirzepatide), and Saxenda (liraglutide). These require a clinical assessment and prescription from a GP or specialist.
Clinical trials show that Wegovy can help adults lose an average of around 15% of body weight, while Mounjaro users in trials lost 15–21% on average. Both are used alongside reduced-calorie diet and increased physical activity. Access is available through NHS specialist weight management services (though waiting lists vary by region) or through private online prescribing following a clinical assessment. Our GLP-1 weight loss calculator can help you estimate potential results at different doses.
NHS weight loss support is also available through your GP at tier 1 and 2 levels, including behaviour change programmes and digital tools. For prescription weight loss medication through the NHS, you'll typically be referred to a tier 3 specialist weight management service if you meet eligibility criteria (BMI 30+, or 27+ with weight-related health conditions). Your GP can assess your individual needs and discuss what options are appropriate for you.
- 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 there effective over the counter weight loss pills I can buy without a prescription in the UK?
There are very few truly effective OTC weight loss pills in the UK. Orlistat (60mg) is available from pharmacies without prescription, and various herbal supplements exist, but they have limited clinical evidence. Prescription medications like Wegovy and Mounjaro are far more effective for significant weight loss — these require a clinical assessment and prescription from a healthcare professional.
What's the difference between OTC weight loss pills and prescription weight loss injections?
OTC pills typically contain caffeine, herbal extracts, or fibre with modest effects. Prescription GLP-1 injections like Wegovy work by activating hormonal pathways that reduce appetite and food cravings. Clinical trials show prescription injections produce much greater average weight loss — 15–21% of body weight — compared to OTC options, but they require a prescription and clinical assessment.
How do I access prescription weight loss medication in the UK?
You can access prescription weight loss medication through the NHS (referral to specialist tier 3 services, though waiting lists vary) or privately through an online consultation with a UK-licensed prescriber. Both routes require a clinical assessment to confirm you meet eligibility criteria. Your GP can discuss NHS options, or you can explore private prescribing independently through registered providers.
What does the NHS recommend for weight loss?
The NHS recommends a tiered approach starting with self-help, digital tools, and community programmes (tier 1), then GP-based behaviour change support (tier 2), then specialist weight management services where prescription medication may be offered (tier 3). Try our free BMI calculator to understand your current health status and discuss options with your GP.
Can I use my BMI to check if I'm eligible for weight loss medication?
Yes. Generally, prescription weight loss medication in the UK is available for adults with BMI 30+, or BMI 27+ with weight-related health conditions like type 2 diabetes or high blood pressure. However, eligibility assessment also depends on your individual health. Use our free BMI calculator to check your current BMI, then discuss your options with your GP or a licensed prescriber.
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.