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
Does Vitamin C Help With Weight Loss?
Vitamin C is often promoted as a weight loss supplement, but the evidence for direct weight loss is limited. While vitamin C plays important roles in your body — including immunity and collagen production — there's no strong scientific evidence that taking extra vitamin C will help you lose weight. However, good nutrition (including adequate vitamin C) is essential for any sustainable weight management UK programme. If you're looking to manage your weight effectively, focus on proven methods like calorie reduction, physical activity, and where appropriate, prescription weight loss medication alongside lifestyle changes.
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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.
What Does the Evidence Actually Say About Vitamin C?
Several studies have looked at whether vitamin C supplements aid weight loss, with mixed and generally underwhelming results. A few small studies suggest vitamin C may play a minor role in fat oxidation during exercise, but the effect is modest at best and not clinically significant for most people.
The NHS and NICE do not recommend vitamin C supplementation specifically for weight loss. What matters much more for sustainable weight management is:
- Calorie deficit — eating fewer calories than you burn
- Physical activity — both cardiovascular and strength training
- Balanced nutrition — including whole foods with natural vitamin C (citrus, berries, peppers)
- Behavioural change — developing sustainable eating habits
If you have a BMI in the overweight or obese range, calculate your personal BMI using our free BMI calculator above to see where you stand against NHS guidelines. For significant weight loss, prescription weight loss medication such as GLP-1 injections may be recommended by your GP alongside lifestyle changes.
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.
What Actually Works for Weight Loss in the UK?
Proven weight loss approaches include: a reduced-calorie diet (typically 500 kcal deficit per day for 0.5 kg/week loss), regular physical activity, and behaviour change support through NHS weight loss programmes or tier 3 specialist services.
For adults with a BMI of 30 or above, or 27–29.9 with weight-related conditions like type 2 diabetes or high blood pressure, prescription weight loss medication may be considered. Prescription weight loss injections such as Mounjaro and Wegovy have shown clinically significant results in trials — Wegovy users lost an average of 15% body weight in the STEP trial.
Try our free weight loss calculator to explore how prescription GLP-1 medication might support your goals alongside diet and exercise. Track your progress with our free progress tracker to stay motivated.
- 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.
Does taking vitamin C supplements help you lose weight?
No strong scientific evidence supports vitamin C supplementation for weight loss. While vitamin C is essential for health, taking extra will not directly help you shed pounds. Weight loss depends on calorie deficit, physical activity, and behaviour change — not vitamins alone.
Is vitamin C important for a healthy diet during weight loss?
Yes. Vitamin C supports immunity and collagen health, but you get plenty from whole foods like oranges, strawberries, and peppers. You do not need supplements if you eat a balanced diet. Focus on overall calorie intake and nutritional quality rather than single supplements.
What are the proven methods for weight loss in the UK?
The NHS recommends: calorie deficit (500 kcal/day for ~0.5 kg/week loss), physical activity, and behaviour support. For BMI 30+, or 27–29.9 with health conditions, your GP may refer you to tier 3 weight management services or discuss prescription weight loss medication options.
Can prescription weight loss injections help if diet alone isn't working?
Yes. GLP-1 medications like Wegovy and Mounjaro are prescription-only and available through NHS specialist services or private prescribing. Clinical trials show average weight loss of 15–21% body weight. They work best alongside reduced calories and exercise. Speak to your GP about eligibility.
Where do I start if I want to lose weight?
Calculate your BMI using our free BMI calculator to understand where you are against NHS guidelines. Then discuss weight management options with your GP — this might include tier 1 programmes, lifestyle support, or if appropriate, prescription medication. Track your progress with our free progress tracker.
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.