Sertraline
Is It Right for You?
A complete guide to Sertraline — what it treats, how it works, dosages, side effects, and when a clinician may prescribe it following an online consultation.
What Is Sertraline?
Sertraline is a selective serotonin reuptake inhibitor (SSRI) – one of the most widely prescribed classes of antidepressant medication in the world. It is used to treat a broad range of mental health conditions including depression, anxiety disorders, obsessive-compulsive disorder (OCD), post-traumatic stress disorder (PTSD), and panic disorder. In the UK, sertraline is one of the most commonly prescribed antidepressants in primary care and is recommended as a first-line treatment by the National Institute for Health and Care Excellence (NICE) for several of these conditions.
First approved in the early 1990s, sertraline has accumulated an extensive evidence base supporting its efficacy and safety across a wide range of conditions and patient populations. It is favoured for its relatively favourable side effect profile compared to older antidepressants such as tricyclics and MAOIs, its low potential for drug interactions compared to other SSRIs such as fluoxetine and fluvoxamine, and its suitability for use in a wide range of patients including the elderly and those with comorbid physical health conditions.
Sertraline is available in tablet and oral concentrate solution forms and is suitable for adults and children over 6 years of age for certain indications. It is available generically and under the brand name Lustral in the UK.
Sertraline is a prescription-only medication in the UK. A licensed clinician must assess your symptoms and medical history before it can be prescribed – which can now be done quickly and conveniently through a telehealth consultation.
What Conditions Is Sertraline Used For?
Sertraline is licensed and used for a range of mental health conditions:
first-line pharmacological treatment for moderate to severe depression; reduces core depressive symptoms including low mood, anhedonia, fatigue, and hopelessness.
reduces persistent, excessive worry and associated physical symptoms of anxiety.
reduces the frequency and severity of panic attacks and the anticipatory anxiety associated with them.
reduces anxiety in social situations and improves functioning in social and occupational settings.
licensed for use in adults and children aged 6 years and above; reduces the frequency and distress of obsessions and compulsions.
reduces re-experiencing symptoms, hyperarousal, avoidance, and associated depression in PTSD.
reduces the severe mood and physical symptoms associated with PMDD when taken either continuously or during the luteal phase of the menstrual cycle.
Unlike many medications that produce effects within hours, sertraline typically requires 2 to 6 weeks of regular use before meaningful improvements in mood and anxiety are noticed. Full therapeutic benefit may take 8 to 12 weeks. It is important not to stop taking sertraline prematurely because of the initial delay in effect. Many patients experience some side effects before they experience benefits – this is normal and expected.
How Does Sertraline Work?
Sertraline belongs to the selective serotonin reuptake inhibitor (SSRI) class of antidepressants and works primarily by increasing the availability of serotonin in the synaptic cleft – the gap between nerve cells through which chemical signals are transmitted.
Under normal circumstances, after serotonin is released from a nerve terminal and binds to receptors on adjacent neurons, it is transported back into the releasing neuron via a protein called the serotonin transporter (SERT) – a process known as reuptake. This recycling mechanism limits the duration and intensity of serotonergic signalling.
Sertraline selectively binds to and inhibits the serotonin transporter, blocking the reuptake of serotonin from the synapse back into the presynaptic neuron. This causes serotonin to accumulate in the synaptic cleft, prolonging and enhancing its effects on postsynaptic receptors. The resulting increase in serotonergic neurotransmission is associated with improvements in mood, anxiety, emotional regulation, and cognitive function.
The selectivity of sertraline for the serotonin transporter – with minimal effects on noradrenaline, dopamine, histamine, or muscarinic receptors – is what gives SSRIs their more favourable side effect profile compared to older antidepressants such as tricyclics, which act on multiple receptor systems simultaneously.
It is important to understand that the initial increase in serotonin availability is not itself directly responsible for the antidepressant effect. The therapeutic benefits of sertraline appear to result from longer-term downstream changes in receptor sensitivity, neuroplasticity, and gene expression that occur over weeks of sustained serotonin signalling – which explains the delay of several weeks before full therapeutic effects are experienced.
Sertraline also has modest inhibitory effects on the dopamine transporter, which may contribute to its efficacy in OCD and PTSD, and mild sigma-1 receptor binding activity that may play a role in its anxiolytic effects.
Dosages & Administration
The correct dose depends on the type and severity of infection, age, weight, and kidney function. Always follow your clinician's instructions. The table below is for general reference only.
Administration Tips
Sertraline can be taken with or without food. Taking it with food may reduce the likelihood of nausea, which is one of the most common early side effects.
Take sertraline at the same time each day – either morning or evening, whichever you prefer and are most likely to remember consistently. Some patients prefer morning dosing to avoid potential sleep disturbance; others find evening dosing reduces daytime nausea.
Start low and go slow. Sertraline is typically started at 25 to 50 mg and increased gradually in 25–50 mg increments every 2 to 4 weeks as tolerated. Rapid dose increases are associated with a higher incidence of side effects. Your clinician will advise on the appropriate titration schedule.
Do not stop sertraline abruptly. Stopping suddenly can cause discontinuation syndrome – a cluster of symptoms including dizziness, nausea, flu-like feelings, electric shock sensations ("brain zaps"), irritability, and low mood. Always taper the dose gradually under medical supervision when stopping.
Be patient. It typically takes 2 to 6 weeks before meaningful improvements in mood and anxiety are noticed, and up to 12 weeks for full therapeutic benefit. Do not stop taking sertraline because of a perceived lack of effect in the first few weeks – this is normal.
Side Effects of Sertraline
Side effects are most common in the first 1 to 2 weeks of treatment and often resolve as the body adjusts to the medication. Serious side effects are uncommon but require prompt medical attention.
- Nausea (most common early side effect; usually resolves within 1–2 weeks)
- Diarrhoea or loose stools
- Dry mouth
- Insomnia or sleep disturbance
- Headache
- Dizziness
- Fatigue or drowsiness
- Sweating (including night sweats)
- Sexual dysfunction – reduced libido, delayed ejaculation, or difficulty reaching orgasm
- Appetite changes and weight changes (more commonly weight gain with long-term use)
- Tremor
- Suicidal thoughts or self-harm ideation – particularly in children, adolescents, and young adults in the early weeks of treatment; any new or worsening thoughts of suicide or self-harm require immediate medical attention
- Serotonin syndrome – a rare but potentially life-threatening condition caused by excessive serotonergic activity; symptoms include agitation, confusion, rapid heart rate, high temperature, muscle twitching, and excessive sweating; usually occurs when sertraline is combined with other serotonergic drugs
- Hyponatraemia (low sodium) – particularly in elderly patients; symptoms include headache, confusion, weakness, and seizures
- Severe allergic reaction – hives, facial swelling, difficulty breathing, collapse
- QT prolongation – rare cardiac arrhythmia risk, particularly at high doses or in combination with other QT-prolonging drugs
- Abnormal bleeding – SSRIs reduce platelet aggregation, increasing the risk of bleeding, particularly gastrointestinal bleeding when combined with NSAIDs or anticoagulants
- Mania or hypomania – may unmask or trigger manic episodes in patients with undiagnosed bipolar disorder
- Seizures – rare; risk is higher in patients with a history of epilepsy
Clinical trials have shown an increased risk of suicidal thoughts and behaviour in children, adolescents, and young adults (up to age 25) during the early weeks of antidepressant treatment. This does not mean the medication causes suicide, but all patients – particularly those under 25 – should be closely monitored for new or worsening suicidal ideation, agitation, or unusual behavioural changes in the early weeks of treatment. If such symptoms occur, seek immediate medical attention.
Drug Interactions
Always disclose all prescription drugs, over-the-counter medicines, vitamins, and supplements to your clinician or pharmacist before starting sertraline.
Combining sertraline with MAOIs can cause potentially fatal serotonin syndrome. Sertraline must not be started within 14 days of stopping an MAOI (or 21 days for moclobemide). Conversely, an MAOI must not be started within 14 days of stopping sertraline. This combination is absolutely contraindicated.
Combining sertraline with other serotonergic medications significantly increases the risk of serotonin syndrome. Tramadol in particular is frequently co-prescribed and requires caution. St John's Wort – an over-the-counter herbal remedy – can also cause serotonin syndrome when combined with SSRIs and must be avoided.
Sertraline increases plasma levels of pimozide, raising the risk of QT prolongation and serious cardiac arrhythmia. This combination is contraindicated.
SSRIs reduce platelet aggregation, which combined with anticoagulants or antiplatelet drugs significantly increases the risk of bleeding. INR should be monitored in patients on warfarin when starting or stopping sertraline. Concomitant use of NSAIDs with sertraline should be avoided where possible due to the increased risk of gastrointestinal bleeding.
Concurrent use of NSAIDs with SSRIs significantly increases the risk of gastrointestinal bleeding. If NSAIDs are necessary, a proton pump inhibitor (PPI) should be co-prescribed for gastroprotection.
Concurrent use of sertraline with lithium can increase serotonergic effects and the risk of serotonin syndrome, as well as lithium toxicity. The combination can be used under careful specialist supervision with close monitoring of lithium levels.
Sertraline may affect the blood levels of certain antiepileptic drugs, requiring dose adjustments and closer monitoring of drug levels. Conversely, some antiepileptics may reduce sertraline levels through enzyme induction.
Sertraline may increase plasma levels of some antipsychotics, raising the risk of side effects including QT prolongation. Caution and monitoring are required.
Sertraline does not have a dangerous pharmacokinetic interaction with alcohol, but alcohol is a CNS depressant that can worsen the symptoms of depression and anxiety. Regular alcohol consumption is likely to undermine the therapeutic benefit of sertraline and is generally discouraged in patients being treated for depression or anxiety.
Important Warnings
Serotonin syndrome is a potentially life-threatening condition that can occur when sertraline is combined with other serotonergic drugs or when doses are significantly increased. Symptoms include confusion, agitation, rapid heart rate, high blood pressure, dilated pupils, muscle twitching or rigidity, high temperature, and excessive sweating. If these symptoms develop, stop sertraline and seek emergency medical attention immediately.
The combination of sertraline with monoamine oxidase inhibitors is absolutely contraindicated due to the risk of fatal serotonin syndrome. A 14-day washout period between stopping an MAOI and starting sertraline – and vice versa – is mandatory. Always inform every clinician and pharmacist you see that you are taking sertraline.
Stopping sertraline abruptly or missing several doses can cause a discontinuation syndrome characterised by dizziness, nausea, flu-like symptoms, sensory disturbances ("brain zaps"), irritability, and emotional instability. These symptoms are not dangerous but can be distressing. Always taper sertraline gradually over several weeks under medical supervision when stopping treatment.
SSRIs including sertraline can cause low sodium levels (hyponatraemia), particularly in elderly patients, those taking diuretics, or those with low fluid intake. Symptoms include headache, difficulty concentrating, memory problems, weakness, and in severe cases seizures or coma. Sodium levels should be checked if these symptoms develop.
Sertraline reduces platelet aggregation and increases the risk of abnormal bleeding, particularly gastrointestinal bleeding. Risk is substantially higher when combined with NSAIDs, aspirin, or anticoagulants. Inform your clinician and any other healthcare provider that you are taking sertraline before undergoing surgery or dental procedures.
Sertraline, like all antidepressants, can trigger manic or hypomanic episodes in patients with bipolar disorder. If you have a personal or family history of bipolar disorder, inform your clinician before starting sertraline. Antidepressants in bipolar disorder should only be prescribed alongside a mood stabiliser and under specialist supervision.
Sertraline is one of the better-studied antidepressants in pregnancy and is often considered the preferred SSRI when antidepressant treatment is necessary during this period. Use in late pregnancy has been associated with neonatal adaptation syndrome (transient symptoms in the newborn including jitteriness, feeding difficulties, and mild respiratory distress) and, rarely, persistent pulmonary hypertension of the newborn (PPHN). The decision to use sertraline during pregnancy should involve a careful discussion of the risks of untreated depression against the potential risks of medication. Sertraline passes into breast milk in small amounts; it is considered one of the preferred antidepressants during breastfeeding based on available evidence. Always discuss with your clinician.
Speak to a Clinician About Treatment
Getting advice no longer means sitting in a waiting room. Through The GP Service, you can consult with a licensed clinician in minutes — from home, on your lunch break, or wherever works for you. If treatment is clinically appropriate, your clinician can issue a prescription during the consultation. A consultation does not guarantee a prescription.
The treatment you need, when you need it.
Sertraline FAQs
Yes. A licensed clinician can assess your symptoms and mental health history via a telehealth consultation and prescribe sertraline if it is clinically appropriate. Prescriptions are typically sent to your preferred pharmacy the same day, often within minutes of your consultation.
Sertraline typically takes 2 to 6 weeks before meaningful improvements in mood, anxiety, or other symptoms are noticed. Full therapeutic benefit may take 8 to 12 weeks. Some patients notice improvements in sleep, appetite, and energy in the first 1 to 2 weeks before mood itself lifts. It is important to continue taking sertraline consistently during this period and not to stop due to a perceived lack of effect in the early weeks.
Sertraline does not change who you are or alter your personality. It works by correcting an imbalance in brain chemistry that is causing symptoms of depression or anxiety. Most patients describe feeling more like themselves – less burdened by depression or anxiety – rather than feeling different or unlike themselves. If you feel emotionally blunted or unlike yourself, discuss this with your clinician.
Not necessarily. For a first episode of depression, guidelines typically recommend continuing sertraline for at least 6 to 12 months after symptoms have fully resolved to reduce the risk of relapse. For recurrent or chronic depression, longer-term treatment may be recommended. For anxiety disorders, treatment duration varies. Your clinician will review your treatment regularly and discuss when and how to taper the medication when appropriate.
There is no dangerous pharmacokinetic interaction between alcohol and sertraline, but alcohol is a depressant that worsens the symptoms of depression and anxiety and undermines the therapeutic benefits of sertraline. Regular or heavy alcohol consumption is strongly discouraged during sertraline treatment. Occasional moderate consumption is unlikely to cause a serious problem for most people, but you should discuss your alcohol intake with your clinician.
Weight changes are possible with sertraline. In the short term, some patients experience appetite loss and mild weight reduction. With longer-term use, modest weight gain is more commonly reported. The extent varies significantly between individuals. If weight change is a concern, discuss this with your clinician.
Brain zaps are brief, electrical shock-like sensations in the head that are one of the most distinctive symptoms of SSRI discontinuation syndrome. They occur because the brain has adapted to the presence of sertraline and experiences a period of adjustment when the drug is removed. They are not dangerous but can be unsettling. Tapering sertraline gradually rather than stopping abruptly significantly reduces the likelihood and severity of discontinuation symptoms.
Sertraline is one of the most studied and commonly used antidepressants during pregnancy and is often the preferred choice when treatment is necessary. The decision involves weighing the risks of untreated depression or anxiety against the potential risks of medication exposure. Your clinician will discuss this with you in detail to support an informed decision.
Sertraline is licensed for use in children aged 6 years and above for OCD. Its use in children and adolescents for depression and anxiety requires careful consideration, close monitoring – particularly for suicidal ideation – and is typically managed in consultation with child and adolescent mental health services (CAMHS).
Take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed one and continue as normal. Do not double up. Try not to miss doses, as consistency is important for maintaining stable blood levels and minimising the risk of discontinuation symptoms.