SSRI Basics: What You Should Know

SSRI stands for selective serotonin reuptake inhibitor. These are the most commonly prescribed antidepressants—names you’ll hear a lot include fluoxetine (Prozac), sertraline (Zoloft), citalopram, escitalopram, and paroxetine. People take SSRIs for depression, anxiety, OCD, panic disorder, and some pain-related conditions. They target serotonin, a brain chemical that helps stabilize mood.

How SSRIs work and what to expect

SSRIs block the reabsorption (reuptake) of serotonin in brain cells, which raises serotonin levels in the spaces between neurons. That change helps mood regulation over time. Don’t expect overnight fixes—most people start to feel some improvement in 2–4 weeks and clearer benefit by 6–8 weeks. Energy and sleep may change before mood improves.

Common early effects: nausea, mild headache, loose stools, or trouble sleeping. Many of these ease after a week or two. Long-term issues that some people notice include sexual side effects (lower libido, delayed orgasm), small weight changes, and sometimes emotional blunting. If side effects are serious or persistent, talk to your prescriber—switching to a different SSRI or adjusting dose often helps.

Practical tips: starting, safety, and stopping

Start low and go slow—do what your doctor recommends. Take your pill at the same time every day to build a routine. If it causes stomach upset, take with food. Keep a simple log of symptoms for the first 6–8 weeks so you can track changes and share that with your clinician.

Watch for dangerous interactions: don’t combine SSRIs with MAO inhibitors. Mixing with other serotonergic drugs (like triptans for migraine, some migraine preventives, or St. John's wort) can raise the risk of serotonin syndrome. Signs of serotonin syndrome include high fever, fast heartbeat, agitation, severe muscle stiffness, and confusion—seek emergency care if that happens.

SSRIs can increase bleeding risk when taken with blood thinners (warfarin/Coumadin) or NSAIDs; your INR or bleeding signs may need closer monitoring. If you’re on blood thinners, mention any new antidepressant to the clinician managing your anticoagulation.

Stopping SSRIs abruptly can cause withdrawal-like symptoms: dizziness, electric-shock sensations, irritability, flu-like symptoms, and sleep problems. Taper slowly under medical advice. Fluoxetine has a longer half-life and often causes fewer withdrawal symptoms; others (like paroxetine) can cause more noticeable discontinuation effects.

Pregnancy and breastfeeding need a specific plan—some SSRIs carry different risks, so discuss options with your doctor or obstetrician. Also mention any herbal remedies or over-the-counter meds you use.

Final practical checks: keep a list of all meds, report new or worsening suicidal thoughts (especially in young adults and teens), and schedule a follow-up 2–4 weeks after starting. If the first SSRI doesn’t help, a second try or an alternative treatment often does. Talk openly with your clinician—small changes in dose or drug can make a big difference in how you feel.