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 Ascorbic Acid Help with Weight Loss?
Ascorbic acid (vitamin C) is often mentioned online as a potential weight loss aid, but the evidence for its direct effect on weight management in the UK is limited. While vitamin C plays important roles in metabolism and immune function, taking ascorbic acid supplements alone is not an evidence-based weight loss strategy. For sustainable weight management, the NHS recommends a combination of reduced-calorie diet, increased physical activity, and—where appropriate—prescription weight loss medication. Our free BMI calculator can help you understand where you currently sit on the health spectrum.
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 Does Research Actually Show About Ascorbic Acid?
Clinical research on ascorbic acid and weight loss shows modest, inconsistent results. Some small studies suggest vitamin C may help with fat oxidation during exercise or support metabolic function, but these effects are typically minor and do not lead to significant weight loss on their own.
The reality is that no supplement alone causes meaningful weight loss. Weight loss requires a calorie deficit—eating fewer calories than you burn. Ascorbic acid does not suppress appetite or significantly increase calorie burning in the way that evidence-based prescription weight loss medications do.
In the UK, prescription GLP-1 medications like Mounjaro and Wegovy have clinical trial evidence showing 15–21% average body weight loss. These work through different biological mechanisms: they reduce appetite and help regulate blood sugar. By contrast, vitamin C supplements lack this level of evidence for weight management.
Clinically BackedWeight Loss
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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.
Evidence-Based Weight Loss Strategies That Actually Work
If you're looking to lose weight, the NHS recommends starting with sustainable lifestyle changes: a reduced-calorie diet of 500 kcal per day below your needs, plus regular physical activity. This typically results in losing 0.5–1 kg per week.
For those with a BMI of 30 or above, or 27–29.9 with weight-related health conditions like type 2 diabetes or high blood pressure, prescription weight loss treatment may be appropriate. Your GP can assess your eligibility or refer you to a specialist weight management service. You can also use our GLP-1 weight loss calculator to explore projected outcomes with medication-supported approaches.
- 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.
Is ascorbic acid (vitamin C) effective for weight loss?
Evidence shows ascorbic acid alone is not effective for meaningful weight loss. While vitamin C supports overall health and metabolism, it doesn't suppress appetite or create the calorie deficit needed for weight loss. Evidence-based approaches include calorie reduction, physical activity, and—where eligible—prescription weight loss medication.
Can vitamin C supplements help me burn more calories?
Vitamin C may support metabolic function, but the effect is minimal and insufficient for weight loss on its own. Research shows no significant increase in calorie burning from vitamin C supplementation. Real weight loss requires a calorie deficit of around 500 kcal per day alongside physical activity.
What weight loss methods does the NHS recommend?
The NHS recommends a reduced-calorie diet (500 kcal daily deficit), increased physical activity, and behaviour change support. For eligible adults with BMI ≥30, or BMI 27–29.9 with weight-related conditions, prescription weight loss medication may be offered through specialist services or private prescribing.
Are prescription weight loss injections like Wegovy or Mounjaro more effective than supplements?
Yes. Wegovy and Mounjaro are GLP-1 medications with strong clinical trial evidence. Wegovy showed ~15% average weight loss in STEP trials, and Mounjaro showed 15–21% in SURMOUNT trials. Both require a prescription and clinical assessment. Supplements like ascorbic acid have no equivalent evidence for weight loss.
Where can I get help with weight management in the UK?
Start with your GP, who can discuss lifestyle changes and assess your eligibility for prescription weight loss treatment through NHS specialist services. Alternatively, private online prescribing services are available following a clinical assessment. Use our BMI calculator and weight converter to understand your current health position.
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.