SSRI: What They Do, Side Effects, and How to Use Them Safely

SSRIs (selective serotonin reuptake inhibitors) are a common class of antidepressants used for depression, anxiety, PTSD, OCD, and some pain conditions. They raise serotonin levels in the brain by blocking its reabsorption, helping mood and anxiety symptoms improve over weeks. People start to feel better usually within 2–6 weeks, but full effect can take longer.

Common SSRIs include fluoxetine (Prozac), sertraline (Zoloft), citalopram (Celexa), escitalopram (Lexapro), and paroxetine (Paxil). Each drug has small differences: some stay in the body longer, some may cause more drowsiness, and some interact with other medicines more. Your doctor will pick one based on symptoms, other health issues, and drug interactions.

Side effects and warning signs

Typical side effects are nausea, sleep changes, dry mouth, sweating, and sexual problems. These often settle after a few weeks. Watch closely for sudden mood changes, increased suicidal thoughts (especially in young people), severe agitation, or signs of serotonin syndrome—high fever, tremor, fast heartbeat, and confusion. If you see these, get medical help right away.

Stopping SSRIs suddenly can cause withdrawal symptoms like dizziness, flu-like feelings, and electric shock sensations. Tapering off slowly under a doctor’s plan reduces this risk. Also avoid mixing SSRIs with MAO inhibitors or certain herbal supplements like St. John’s Wort without medical advice—combining them can trigger dangerous serotonin excess.

Practical tips for taking SSRIs

Take the pill at the same time each day. If it causes drowsiness, take it at night; if it wakes you, take it in the morning. Give a new medication at least four to six weeks before judging whether it helps. Keep a simple log of mood, sleep, and side effects to discuss with your clinician.

If one SSRI is not enough, clinicians sometimes switch drugs or add another medication like bupropion or an atypical antipsychotic. Combining treatments can help but raises the chance of side effects, so decisions should be guided by careful follow-up visits. Pregnant or breastfeeding people should discuss risks and benefits with their doctor—some SSRIs are safer than others in pregnancy.

Interactions matter: tell your provider and pharmacist all prescription drugs, over-the-counter meds, and supplements you take. Blood thinners, migraine drugs, and some antibiotics can interact with SSRIs. Your provider may choose a different antidepressant if interactions look risky.

Want more info? This tag page lists articles on related topics—combination therapy, alternatives when a drug doesn’t work, and safety tips for buying meds online. Use those posts to get practical next steps and questions to ask your prescriber.

When you visit your doctor, bring a short list: current meds, past reactions to antidepressants, alcohol or drug use, pregnancy plans, and any medical conditions like liver disease. Ask how long to try treatment, when to expect benefits, what to do about side effects, and a clear tapering plan if you stop. If cost or access is an issue, ask about generic options or patient assistance programs. Keep follow-ups at least once in the first month.