--- title: "Sertraline: side effects, time to work, stopping" description: "Sertraline is an SSRI for depression, anxiety, OCD and PTSD. Benefit often takes weeks. Do not stop suddenly. Crisis support is 999, 111 or Samaritans…" url: https://healthanswers.co.uk/treatments/sertraline/ robots: noindex --- # Sertraline: side effects, time to work, stopping Treatments Sertraline is an SSRI for depression, anxiety, OCD and PTSD. Benefit often takes weeks. Do not stop suddenly. Crisis support is 999, 111 or Samaritans 116 123. Written by HealthAnswers editorial team Medically reviewed by [Dr Neil Singh MBChB, nMRCGP](https://healthanswers.co.uk/our-doctors/neil-singh/) · GMC 7039648 Reviewed 25 September 2026 ## Quick answer How long does sertraline take to work? Sertraline is an SSRI antidepressant used for depression, anxiety, OCD and PTSD. A GP starts and reviews it. Benefit often takes several weeks. Do not stop suddenly — taper with a GP. If you cannot keep yourself safe, call 999 or Samaritans on 116 123. In England you can often self-refer to NHS Talking Therapies. On this page 10 sections ## Key facts about sertraline - Sertraline is a first-choice SSRI on the NHS for depression and many anxiety problems. - Mood benefit often takes 4 to 6 weeks — early side effects can appear sooner. - Do not stop suddenly; a GP plans a taper. - Extra monitoring is used when starting treatment under 25. - Crisis support is 999 if you cannot stay safe, or Samaritans on 116 123. - This page is not a tablet-strength or titration guide. ## Should I use this page, or skip it? Use this page if a GP has mentioned sertraline or you already take it and want the next-step rules. Skip it and call 999 or Samaritans on 116 123 if you cannot keep yourself safe. This page cannot prescribe or give a dose. Do not start a partner’s leftover pack. Do not stop yours because a forum said to. ## What is sertraline for? Sertraline is an SSRI used for [depression](https://healthanswers.co.uk/conditions/depression/), [anxiety](https://healthanswers.co.uk/conditions/anxiety/), [OCD](https://healthanswers.co.uk/conditions/obsessive-compulsive-disorder/) and PTSD. It changes chemical signalling over weeks, not hours. It is not a sedative for tonight’s panic, though some people feel more settled with time. A GP chooses it because the evidence fits your problem. A GP chooses it because the evidence fits your problem, not because it is “the strongest”. Other [antidepressants](https://healthanswers.co.uk/treatments/antidepressants/) exist if this one does not suit you. ## What should I expect in the first weeks? [Nausea](https://healthanswers.co.uk/symptoms/feeling-sick/) and a slightly wired or flat feeling can come before mood lifts. Take it as directed, usually at the same time each day. Some people notice sleep or anxiety changes within 1 to 2 weeks. The full mood benefit often takes 4 to 6 weeks. If you feel much more agitated or have new suicidal thoughts, contact a GP or 111 the same day. Under-25s are monitored more closely at the start for that reason. ## What are the side effects of sertraline? Most side effects are mild and settle within the first couple of weeks as your body adjusts, although some last longer. Common ones include: - feeling sick or being sick - headaches - feeling dizzy or drowsy - a [dry mouth](https://healthanswers.co.uk/symptoms/dry-mouth/) - [diarrhoea](https://healthanswers.co.uk/symptoms/diarrhoea/) - trouble sleeping - a lower sex drive or other sexual problems - putting on weight Do not drive, cycle or use machinery while you feel dizzy or drowsy. If a side effect bothers you or does not settle, talk to a pharmacist or GP, and keep taking sertraline unless you are told to stop. Serious side effects are rare. Call 999 for signs of a severe allergic reaction, such as a swollen tongue or throat, or a raised itchy rash with difficulty breathing. Call 111 or your GP urgently for: - a fast heartbeat, sweating, shaking, twitching muscles and feeling confused or agitated, which can be serotonin syndrome - feeling unusually high or full of energy, or taking risks you normally would not - thoughts of harming yourself or ending your life (call 999 if you cannot keep yourself safe) The leaflet in the pack lists every known side effect. You can report a suspected side effect to the MHRA through the [Yellow Card scheme](https://yellowcard.mhra.gov.uk/). ## Can I take other medicines or drink alcohol? Tell a GP and pharmacist about every tablet and supplement, including St John’s wort, [migraine](https://healthanswers.co.uk/conditions/migraine/) medicines, and other antidepressants. Mixing serotonergic drugs can be dangerous. A pharmacist can check your list — find a GPhC-registered pharmacy on [Pick My Pharmacy](https://pickmypharmacy.co.uk/). Heavy drinking worsens depression and drowsiness. Ask before using alcohol to sleep. This page does not list milligram interactions. ## How do I stop, and what about therapy? Plan a taper with a GP rather than stopping overnight. Sudden stops cause [dizziness](https://healthanswers.co.uk/symptoms/dizziness/), flu-like feelings, irritability or electric-shock sensations. Needing a taper is not the same as alcohol addiction. [Talking therapies](https://healthanswers.co.uk/treatments/talking-therapies/) remain useful alongside or instead of tablets. In England you can often self-refer to NHS Talking Therapies. In Scotland, Wales and Northern Ireland, ask a GP. ## What if I am pregnant or planning a baby? Tell a GP before you start, stop, or change sertraline if you are pregnant, trying to conceive, or breastfeeding. Do not stop overnight because of a forum scare. A clinician can weigh untreated depression against medicine risks for you. This page cannot make that call. If you cannot keep yourself safe in pregnancy, that is still 999 or a crisis line, not a wait for antenatal clinic. ## When is it 111 or 999? Call 999 if you cannot keep yourself safe. Call Samaritans on 116 123 or text SHOUT to 85258 any time. Call 111 for urgent mental health advice in England, Scotland (NHS 24) and Wales if it is not 999. In Northern Ireland use GP out-of-hours on [nidirect](https://www.nidirect.gov.uk/articles/gp-out-hours-services). ## Do NHS doors differ across the UK? Call 111 in England, Scotland and Wales if you need urgent advice and are not in immediate danger; Northern Ireland uses GP out-of-hours via nidirect. Talking therapies are often self-referral in England and GP-led elsewhere. 999 is the same emergency number everywhere. Samaritans on 116 123 is free from any UK nation. A GP in any nation can start, review or taper sertraline. Do not buy leftover strips online to skip that conversation. If mood worsens after a dose change, make contact the same day rather than waiting for the next booked review. A GP, pharmacist or clinic in any UK nation can still start the right pathway even if the local scheme name differs. Take a list of medicines, and say if you are pregnant, on other tablets, or cannot keep yourself safe. ## Who should skip this page? Skip this page if you are already in crisis and need 999 or Samaritans now. It is not a tablet-strength chart, not a pregnancy-prescribing guide, and not permission to mix with St John’s wort. If panic is the main problem, use [panic attacks](https://healthanswers.co.uk/conditions/panic-attacks/) as well as this medicine page. ## ! Important safety information for sertraline See a GP before starting, changing or stopping sertraline. Contact a GP or NHS 111 promptly if mood worsens, you feel agitated, or you have new thoughts of suicide — especially in the first weeks. Call **999** if you cannot keep yourself safe. Call Samaritans on **116 123** any time. ## Common questions about sertraline How long does sertraline take to work? Some people notice sleep or anxiety changes within 1 to 2 weeks. The full mood benefit often takes 4 to 6 weeks. If little has changed after that, a GP may adjust the plan rather than you stopping overnight. Keep taking it unless you are told to stop. What side effects are common? Nausea, loose stools, headache, dry mouth, sweating, and sleep changes are common early and often ease. Sexual side effects can persist — tell a GP; they can discuss options. Report a rash, swelling, or feeling very restless. This page does not list milligram titration. Can I drink alcohol? Heavy drinking is a bad mix with depression and with drowsiness from the medicine. Occasional light drinking may be acceptable for some people — ask a pharmacist or GP. Do not use alcohol to sleep on sertraline. If drinking is part of why mood is low, say so at the review. How do I stop? Do not stop suddenly. A GP reduces the dose over weeks to lower the chance of dizziness, flu-like feelings, irritability or electric-shock sensations. If those appear, the taper can be slowed. Needing a taper does not mean you are addicted in the way alcohol is. Is talking therapy still worth it? Yes. NICE often recommends therapy alongside or instead of tablets, depending on severity. In England you can usually self-refer to NHS Talking Therapies without a GP letter. Tablets are not a failure of character, and therapy is not a luxury extra. Other nations usually start talking therapies via a GP. ## Sources - [NHS — Side effects of sertraline](https://www.nhs.uk/medicines/sertraline/side-effects-of-sertraline/) - [NHS — Sertraline](https://www.nhs.uk/medicines/sertraline/) - [NHS — Antidepressants](https://www.nhs.uk/mental-health/talking-therapies-medicine-treatments/medicines-and-psychiatry/antidepressants/overview/) - [NHS — Talking therapies](https://www.nhs.uk/mental-health/talking-therapies-medicine-treatments/talking-therapies-and-counselling/nhs-talking-therapies/) ## How we reviewed this page Medically reviewed by [Dr Neil Singh](https://healthanswers.co.uk/our-doctors/neil-singh/), MBChB, nMRCGP General Practitioner · GMC [7039648](https://www.gmc-uk.org/registrants/7039648) Dr Neil Singh is a General Practitioner based in Yorkshire with over a decade of experience working in UK primary care. First published 28 June 2026 Medically reviewed 25 September 2026 Next review due 25 September 2029 or sooner if NHS or NICE guidance changes Written by HealthAnswers editorial team. Published by HealthAnswers (Elite Digital AI Solutions Ltd). [How we review content](https://healthanswers.co.uk/about/how-we-review/) · [Report a problem with this page](mailto:corrections@healthanswers.co.uk?subject=Problem%20with%3A%20Sertraline&body=Page%3A%20https%3A%2F%2Fhealthanswers.co.uk%2Ftreatments%2Fsertraline%2F%0A%0AWhat%20looks%20wrong%20or%20out%20of%20date%3A%0A)