Sertraline
Brand names: Zoloft, Lustral, Serlain
Selective serotonin reuptake inhibitor (SSRI)
Sertraline is one of the most prescribed antidepressants worldwide and a first-line treatment for depression, anxiety, OCD, and PTSD. It typically takes 4–6 weeks to show full effect and should not be stopped abruptly.
Drug Class
Selective serotonin reuptake inhibitor (SSRI)
Category
Mental Health
Forms Available
Tablets (25 mg, 50 mg, 100 mg), Oral solution
How It Works
Sertraline blocks the serotonin transporter (SERT) in presynaptic neurons, preventing the reuptake of serotonin into the neuron. This increases serotonin availability in the synaptic cleft and enhances serotonergic neurotransmission. The antidepressant effect emerges over weeks as downstream neuroadaptation occurs.
What It's Used For
- Major depressive disorder (MDD)
- Generalised anxiety disorder (GAD)
- Panic disorder
- Social anxiety disorder
- Obsessive-compulsive disorder (OCD)
- Post-traumatic stress disorder (PTSD)
- Premenstrual dysphoric disorder (PMDD)
Available Forms
Side Effects
Common Side Effects
- Nausea — common at initiation, usually resolves within 1–2 weeks
- Insomnia or sedation (varies between individuals)
- Headache
- Diarrhoea
- Sexual dysfunction — reduced libido, delayed orgasm (common; persists with treatment)
- Increased sweating
- Dry mouth
Serious Side Effects
- Serotonin syndrome — agitation, tremor, hyperthermia, rapid heart rate; especially with other serotonergic drugs
- Hyponatraemia (low sodium) — in elderly patients; monitor sodium
- Increased bleeding risk — especially with NSAIDs or anticoagulants
- Suicidal ideation — rare; monitor particularly in the first weeks and in patients under 25
- Discontinuation syndrome — dizziness, 'brain zaps', nausea on sudden stopping
Drug Interactions
- MAOIs — absolute contraindication; fatal serotonin syndrome; leave 14-day washout
- Tramadol, triptans, linezolid — serotonin syndrome risk
- NSAIDs and anticoagulants — increased GI bleeding risk
- Warfarin — monitor INR; sertraline can alter anticoagulation
- CYP2D6 substrates (some antipsychotics, tricyclics) — sertraline is a moderate CYP2D6 inhibitor
When to Avoid
- Concurrent MAOI therapy (or within 14 days of stopping)
- Concurrent use of pimozide
Patient Tips
- Side effects often improve after the first 1–2 weeks — try not to stop due to early nausea
- Take at the same time each day; can be taken with food to reduce nausea
- The therapeutic effect on mood typically begins at 2–4 weeks, full effect at 4–8 weeks
- Never stop sertraline abruptly — reduce gradually over weeks under medical guidance
- Tell your doctor about all medications — many drugs interact via serotonin or CYP2D6
- Alcohol can worsen depression and interact with sertraline — minimise consumption
When will it start working?
Sertraline begins working on sleep and appetite within the first 1–2 weeks. Mood, motivation, and energy typically improve at 2–4 weeks, with full therapeutic effect at 4–8 weeks. This delay is often frustrating — it does not mean the drug is not working.
If there is no improvement after 4–6 weeks at an adequate dose, dose optimisation or switching to a different antidepressant should be discussed with your doctor.
How long to take it
Guidelines recommend continuing antidepressants for at least 6 months after remission to reduce the risk of relapse. After a second episode, 2 years of treatment is often recommended. After a third episode, long-term treatment may be advised.
Do not stop because you feel better — the feeling better is partly because the medication is working.
Medical disclaimer
This page is for educational reference only. Always follow the dosage and instructions given by your prescriber or pharmacist. Do not start, stop, or change medicines without medical advice.
Reviewed 2026-06-01 · Looms Medical Team