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
Venlafaxine for Weight Loss — What You Need to Know
Venlafaxine is an antidepressant, not a weight loss medication. While some people experience modest weight loss as a side effect when taking venlafaxine, it is not prescribed or recommended for weight management. If you're looking for effective prescription weight loss treatment in the UK, licensed options like GLP-1 injections are specifically designed for this purpose. This guide explains how venlafaxine affects weight and what evidence-based alternatives are available through the NHS and private prescribing services.
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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 Venlafaxine Affects Body Weight
Venlafaxine is an SNRI (serotonin-noradrenaline reuptake inhibitor) antidepressant prescribed primarily for depression, anxiety, and panic disorder. Weight changes can occur as a side effect, but the direction and magnitude vary significantly between individuals.
- Weight loss: Some patients report modest weight loss (typically 2–5kg) in the first 3–6 months, often due to reduced appetite or increased metabolism
- Weight gain: Others experience weight gain, particularly with long-term use — studies suggest 10–15% of users gain weight
- No change: Many users experience stable weight
Venlafaxine is not licensed for weight loss and should never be prescribed with weight management as the primary goal. If you need help with weight management in the UK, talk to your GP about licensed options including prescription weight loss injections, NHS weight management services, or structured diet programmes.
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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.
Licensed Weight Loss Options in the UK
If you're looking for prescription weight loss treatment, the UK has several licensed medications specifically designed for weight management. GLP-1 receptor agonist injections — such as Wegovy (semaglutide) and Mounjaro (tirzepatide) — are prescription-only medicines that may help reduce appetite and support weight loss when combined with dietary changes and physical activity.
Access is available through NHS specialist tier 3 weight management services or private online prescribing following clinical assessment. You can estimate potential weight loss outcomes using our GLP-1 weight loss calculator. Check your BMI using our free BMI calculator to see if you may be eligible. A GP or licensed prescriber will assess whether prescription weight loss treatment is right for you based on your individual health profile and BMI.
- 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 venlafaxine be used for weight loss?
No. Venlafaxine is an antidepressant and is not licensed or recommended for weight loss. While some people experience weight changes as a side effect, this is not predictable or consistent. If you need weight loss support, speak to your GP about evidence-based options like GLP-1 weight loss injections or NHS weight management programmes.
Does venlafaxine cause weight loss or weight gain?
Venlafaxine can cause either weight loss or weight gain depending on the individual. Some patients lose 2–5kg early on, while others gain weight with long-term use. Most users experience stable weight. Weight changes are not the primary purpose of the medication — speak to your GP if you're concerned about weight changes while taking venlafaxine.
What are licensed prescription weight loss medications in the UK?
The UK has approved GLP-1 receptor agonist injections for weight management, including Wegovy (semaglutide) and Mounjaro (tirzepatide). These are prescription-only and available through NHS specialist services or private prescribing. They are specifically designed for weight loss and supported by clinical trial evidence. Eligibility depends on BMI and individual health factors.
How do GLP-1 injections differ from venlafaxine?
GLP-1 injections are specifically licensed for weight management and work by reducing appetite and helping you feel fuller. Venlafaxine is an antidepressant with a different mechanism. GLP-1 medications have strong clinical trial evidence for weight loss; venlafaxine does not. GLP-1 injections should only be used if clinically appropriate following assessment by a prescriber.
How do I access weight loss treatment on the NHS?
Ask your GP for a referral to a tier 3 specialist weight management service in your area. Services typically offer behaviour change support, structured diet programmes, and (increasingly) access to prescription weight loss injections like Mounjaro or Wegovy. Availability and waiting times vary significantly by region. Private prescribing is also available without NHS referral.
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.