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 Carnitine Help With Weight Loss?
Carnitine is a naturally occurring compound in your body that plays a role in fat metabolism. Many people wonder if carnitine supplements can boost weight loss, but the evidence is mixed. This guide explains how carnitine works, what the research actually shows, and whether it's worth considering as part of your weight management strategy in the UK. We'll also explore evidence-based approaches that NHS research supports for sustainable weight loss.
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 Carnitine Do in Your Body?
Carnitine is an amino acid derivative your body produces naturally, particularly in the liver and kidneys. It has a specific role in metabolism: it transports long-chain fatty acids into the mitochondria (the energy-producing part of your cells) so they can be broken down for energy. This process is called beta-oxidation. Some people believe that taking extra carnitine supplements will accelerate fat burning and increase weight loss. However, your body tightly regulates carnitine levels, and most healthy people already have sufficient carnitine from food sources like meat, fish, dairy, and nuts. Unless you have a genuine carnitine deficiency (which is rare and usually medical), taking supplements doesn't necessarily increase the amount available for fat burning.
- Carnitine is made naturally in your liver and kidneys
- It helps transport fat molecules into cells for energy production
- Most people get enough carnitine from food
- Supplementation does not assures increased fat burning
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 Does Research Show About Carnitine and Weight Loss?
Clinical trials examining carnitine supplementation for weight loss show modest and inconsistent results. Some studies found small reductions in body weight or body fat percentage when carnitine was combined with exercise and calorie restriction, but the effect was generally small—often less than 1–2 kg difference compared to placebo over several months. Most research suggests that any weight loss benefit comes primarily from the calorie deficit and exercise, not the carnitine itself. The NHS and NICE do not recommend carnitine supplements as a primary weight management strategy. For sustainable weight loss in the UK, evidence-based approaches include reducing calorie intake, increasing physical activity, and—where appropriate and clinically assessed—prescription weight management medications. You can calculate your BMI and explore your weight management options using our free tools on this page.
If you're considering weight management options, it's worth knowing what evidence actually supports. Prescription weight loss injections like Mounjaro and Wegovy have shown much stronger clinical evidence than carnitine supplements. Wegovy (semaglutide), for example, is a GLP-1 injection licensed in the UK and helped participants lose an average of around 15% of body weight in clinical trials—significantly more than carnitine supplementation. These medications work through proven mechanisms and require a prescription and clinical assessment. Try our free GLP-1 weight loss calculator to estimate potential outcomes with evidence-based medication. For general weight management, our weight converter and progress tracker can help you track your journey alongside dietary changes and exercise—the foundations of 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.
Is carnitine safe to take as a supplement?
Carnitine supplements are generally considered safe for most people at standard doses (1–3 grams per day). However, some people report side effects including nausea, diarrhoea, or a fishy body odour. People with certain kidney conditions should avoid carnitine. Always consult your GP before starting any supplement, especially if you take other medications.
Can carnitine supplements help me lose weight?
Research shows carnitine has minimal weight loss benefit for most people. Studies found small effects (often under 1–2 kg) when combined with diet and exercise—but the weight loss primarily came from the calorie deficit, not the carnitine. It's not an alternative to proven weight management strategies.
Is carnitine better than prescription weight loss medication?
No. Prescription weight loss medications like Mounjaro and Wegovy have far stronger clinical evidence. Wegovy helped participants lose an average of 15% body weight in trials, whereas carnitine showed minimal independent benefit. Prescription medications require clinical assessment but offer proven results for eligible adults.
What's the difference between L-carnitine and acetyl-L-carnitine?
Both are forms of carnitine with similar functions. Acetyl-L-carnitine crosses the blood-brain barrier more easily and may have some cognitive benefits, but neither form has strong evidence for weight loss. Your GP can advise if either might be relevant to your individual health.
Does the NHS recommend carnitine for weight loss?
No. The NHS recommends sustainable weight loss through calorie deficit, physical activity, and behavioural changes. Prescription weight management medications (assessed by specialist services) have stronger evidence. Carnitine supplements are not part of NHS weight management guidance.
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.