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
Women's Vitamins for Weight Loss — What Works
Vitamins alone won't cause weight loss, but nutritional deficiencies can make weight management harder. A healthy weight loss approach combines adequate micronutrients with a calorie deficit, physical activity, and sometimes prescription medication. The NHS emphasises that sustainable weight loss requires a holistic strategy — not supplements in isolation. This guide explains which nutrients matter, common deficiencies in women, and how they fit into evidence-based weight management. If you're struggling with weight management, our free BMI calculator and GLP-1 weight loss calculator can help you understand your starting point and explore all your options.
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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.
Which Vitamins and Minerals Support Weight Management?
Several micronutrients are important for metabolism and energy, though no single vitamin directly causes weight loss:
- Vitamin D: Low levels linked to obesity and metabolic dysfunction. NHS recommends 10 micrograms daily for UK adults. Many women are deficient, especially in winter.
- B vitamins (B12, folate, B6): Support energy metabolism and may help if deficient, but supplementing when adequate offers no weight loss benefit.
- Iron: Women lose iron through menstruation. Deficiency causes fatigue, making exercise harder. NHS recommends 8.4mg daily for adult women.
- Magnesium: Supports muscle function and metabolism. Deficiency is common but often undiagnosed.
- Zinc: Important for immune function and metabolism, though deficiency-related weight gain is rare in the UK.
The key point: if you have a deficiency, correcting it may support your weight management efforts. But if you're already getting adequate nutrition, additional supplementation won't accelerate weight loss without a calorie deficit.
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.
Vitamins vs. Evidence-Based Weight Loss for UK Women
In the context of weight management UK approaches, vitamins play a supporting role only. The NHS weight loss pathway emphasises three core elements: dietary changes, physical activity, and where appropriate, prescription medication. For women with a BMI of 30 or above, or 25–29.9 with weight-related health conditions, prescription weight loss options like GLP-1 medications (Mounjaro and Wegovy) are available. These prescription-only injections work by appetite regulation and metabolic support — far more effective than vitamins alone. Use our free BMI calculator to check your eligibility status. Vitamins complement this approach by addressing any nutritional gaps, but they are never a substitute for the calorie deficit and lifestyle changes that evidence shows drive sustainable weight loss.
- 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.
Do vitamin supplements help you lose weight?
Vitamins alone don't cause weight loss. If you have a deficiency (e.g., low vitamin D or iron), correcting it may support your energy levels and metabolism, helping you exercise more effectively. But supplementing when already adequate won't accelerate weight loss. Weight loss requires a calorie deficit, physical activity, and lifestyle change — vitamins are supporting players, not drivers.
Which vitamin deficiency is most common in UK women?
Vitamin D deficiency is extremely common, especially October to March. The NHS recommends all UK adults consider a 10-microgram supplement in winter. Iron deficiency is also common due to menstruation, causing fatigue that makes weight management harder. Your GP can test for deficiencies with a simple blood test.
Should I take vitamins if I'm trying to lose weight?
If your diet is balanced and varied, you likely get adequate vitamins from food. However, if you're on a reduced-calorie diet, ensure you're still getting enough nutrients — consider a basic multivitamin or specific supplementation if you have identified deficiencies. Always discuss with your GP or a dietitian before starting supplements.
Is vitamin D important for weight loss?
Vitamin D supports bone health, immunity, and mood — all relevant to long-term health during weight loss. Some research links low vitamin D to obesity, but supplementing normal levels doesn't directly cause weight loss. The NHS recommends 10 micrograms daily for all UK adults, especially in winter when sunlight is limited.
What if prescription weight loss medication is an option for me?
If you're interested in evidence-based weight management support, your GP can assess your eligibility for NHS specialist weight services or private prescription options. Use our free GLP-1 weight loss calculator to explore potential outcomes. Prescription medications work alongside diet and exercise — not instead of them — and they're far more effective than vitamins for weight loss.
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.