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
Coming Off Sertraline and Weight Loss — What You Need to Know
Sertraline (an SSRI antidepressant) can affect appetite and weight, and some people experience weight changes when coming off the medication. This is normal and varies between individuals. Before stopping sertraline, always speak with your GP—sudden discontinuation can cause withdrawal symptoms. Your GP can help you taper safely and discuss strategies for managing weight during and after stopping. Weight management in the UK involves understanding how medications affect your body and working with healthcare professionals on an individualised approach.
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.
How Sertraline Affects Weight and What Happens When You Stop
Sertraline is an SSRI (selective serotonin reuptake inhibitor) that affects neurotransmitters involved in mood, appetite, and metabolism. Some people gain weight on sertraline—typically 1–2 kg over months—while others experience little change. When you stop sertraline, your serotonin levels and appetite regulation gradually normalise, which can lead to weight loss in some individuals.
However, stopping sertraline abruptly is not recommended. Your GP will typically recommend a gradual taper over weeks or months to avoid withdrawal symptoms (discontinuation syndrome), which can include dizziness, brain zaps, mood changes, and anxiety. During this tapering period, your weight may stabilise, decrease, or fluctuate depending on your individual metabolism and eating habits.
- Weight changes vary significantly between individuals
- Tapering takes time—usually 4–8 weeks minimum
- Your GP must supervise the process
- Diet and physical activity remain important regardless of medication status
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.
Managing Weight When Stopping Sertraline — Practical Steps
If you're stopping sertraline and concerned about weight management, work with your GP to create a plan that covers both safe discontinuation and healthy habits. Use our free BMI calculator to track where your BMI sits before, during, and after tapering—this helps you and your GP monitor changes objectively.
Focus on these alongside tapering: eat a balanced diet with adequate protein, stay hydrated, engage in regular physical activity, and manage stress (which can affect appetite and weight independently of medication). Keep a food and mood diary to spot patterns. After you've fully stopped sertraline and your body has adjusted (typically 6–8 weeks post-cessation), if weight management remains difficult, discuss longer-term weight loss strategies with your GP—including prescription weight loss medication if you meet NHS eligibility criteria.
- 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.
Will I definitely lose weight when I stop sertraline?
No. Weight changes vary between individuals. Some people lose weight, others stay the same, and some gain weight. This depends on your metabolism, diet, activity level, and how sertraline affected your appetite personally. Tapering gradually helps minimise fluctuations.
How long does it take for weight to stabilise after stopping sertraline?
Weight typically stabilises 6–8 weeks after fully stopping sertraline, as your body adjusts to normal serotonin levels and appetite regulation. However, individual timelines vary. Keep monitoring your weight during this period and talk to your GP if you have concerns.
Can I use weight loss injections like Wegovy while stopping sertraline?
This requires careful medical assessment. Do not start Wegovy or other GLP-1 weight loss medications while tapering sertraline without explicit GP guidance, as both affect appetite and mood. Always discuss any new medications with your GP before starting, especially when making changes to psychiatric medications.
What should I do if I gain weight after stopping sertraline?
Weight gain after stopping sertraline is possible if your appetite increases or metabolism slows temporarily. Focus on a balanced diet, physical activity, and stress management. If weight gain persists beyond 8 weeks, discuss with your GP—they can rule out other causes and discuss prescription weight loss medication if eligible.
Is it safe to stop sertraline suddenly to avoid weight gain?
No. Stopping sertraline suddenly (cold turkey) can cause serious withdrawal symptoms including dizziness, mood changes, and anxiety. Your GP will recommend a gradual taper over weeks or months. This slower process is safer and may actually result in more stable weight changes than abrupt stopping.
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.