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
Do ADHD Medications Cause Weight Loss?
Yes, some ADHD medications can cause weight loss as a side effect, particularly stimulant medications like methylphenidate and amphetamines. These work by increasing dopamine and noradrenaline in the brain, which can suppress appetite and boost metabolism. However, weight changes vary between individuals — some people experience minimal effect, whilst others may notice more significant changes. Understanding how your ADHD medication affects your weight is important for overall health management alongside NHS weight loss guidance.
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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.
How ADHD Medications Affect Weight
Stimulant medications used to treat ADHD include methylphenidate (Ritalin, Concerta) and amphetamine-based drugs (Adzenys, Elvanse). These increase levels of dopamine and noradrenaline in the brain, which regulate appetite control and energy expenditure. As a result, many people taking these medications report reduced appetite, eating smaller portions, or feeling full more quickly. Some also experience increased energy and activity levels, which can contribute to additional calorie burn.
- Appetite suppression — the most common weight-related side effect
- Increased metabolism — stimulants can raise metabolic rate slightly
- Nausea — can reduce desire to eat in early weeks
- Individual variation — some people experience no weight change at all
Non-stimulant ADHD medications like atomoxetine (Strattera) and guanfacine have less impact on appetite and typically cause minimal weight change. Weight loss from ADHD stimulants is often most noticeable in the first few weeks or months, and the effect may stabilise over time as the body adjusts to the medication.
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.
Weight Management When Taking ADHD Medication
If you're taking ADHD medication and experiencing unintended weight loss, it's important to discuss this with your GP. Significant weight loss can affect nutritional status, energy levels, and overall health. Your GP may recommend increasing calorie intake through nutrient-dense foods, eating more frequent meals, or adjusting your medication timing (taking it after meals rather than before). Some people benefit from tracking their weight loss progress using a simple tracker to monitor changes over time.
For weight management in the UK, use our free BMI calculator to establish a healthy weight baseline for your height. If you're concerned about intentional weight loss or need additional support, NHS weight management services are available through your GP — particularly if you have comorbidities like type 2 diabetes or cardiovascular concerns.
- 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.
Can ADHD medication cause significant weight loss?
Yes, stimulant ADHD medications can cause noticeable weight loss in some people, particularly in the first weeks of treatment. The degree varies — some individuals experience minimal change whilst others lose several kilograms. If weight loss is unintended or concerning, discuss it with your GP to explore solutions like adjusting meal timing or frequency.
Which ADHD medications are most likely to cause weight loss?
Stimulant medications such as methylphenidate and amphetamines are most likely to suppress appetite. Non-stimulant alternatives like atomoxetine (Strattera) and guanfacine typically have minimal impact on weight. Your GP can discuss which medication is most appropriate for you.
Is weight loss from ADHD medication permanent?
Not necessarily. Weight loss is often most pronounced in the early weeks as your body adjusts. After several weeks or months, appetite may normalise and weight may stabilise, even whilst continuing the medication. Individual responses vary considerably.
How can I manage weight loss if I'm taking ADHD medication?
Eat more frequently with nutrient-dense foods, take your medication after meals rather than before to reduce appetite suppression, and aim for adequate protein and healthy fats. Monitor your weight using a free progress tracker. If loss is significant or concerning, contact your GP for personalised guidance.
Are ADHD medications safe if I'm trying to lose weight intentionally?
ADHD medications are prescribed based on clinical need, not for weight loss purposes. If you're considering weight loss treatment alongside ADHD medication, discuss this with your GP or a specialist — prescription weight management options are available through NHS services or private assessment if clinically appropriate.
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.