sertraline
Zoloft (sertraline) is a selective serotonin reuptake inhibitor used for depression, obsessive-compulsive disorder, panic disorder, PTSD, social anxiety disorder, and premenstrual dysphoric disorder. It blocks the serotonin transporter, increasing serotonin signaling in mood and fear circuits. It is one of the most widely prescribed antidepressants.
This page is based on FDA prescribing information for sertraline, cross-checked with MedlinePlus and the National Cancer Institute dictionary; the mechanism is explained in plain language, and analogies are used only where they stay accurate.
How it works
Explains what the medicine does in the body, not dosing, side effects, or safety.
An analogy
Imagine a whiteboard where messages are written in serotonin. Normally, an eraser called SERT wipes the board clean quickly. Sertraline slows that eraser down, so the message stays visible longer — giving the brain's mood and fear circuits more time to 'read' the calming signal.
In simple terms
Sertraline belongs to a group of antidepressants called selective serotonin reuptake inhibitors, or SSRIs. Nerve cells in the brain use a chemical called serotonin to pass messages across the tiny gap between cells. After serotonin delivers its message, a pump called the serotonin transporter pulls it back into the sending cell. Sertraline blocks that pump, so serotonin stays in the gap longer and keeps stimulating the next cell. Over several weeks, this steadier serotonin signaling helps lift mood, reduce obsessive thoughts, calm panic, and ease social fear. Sertraline also has a mild blocking effect on the dopamine transporter, which may contribute to its broad range of uses.
In depth
Sertraline is a naphthalenamine derivative that potently inhibits the neuronal serotonin transporter (SERT), with weaker activity at the dopamine transporter and negligible affinity for the norepinephrine transporter. By blocking SERT, sertraline increases extracellular serotonin in the synaptic cleft, enhancing post-synaptic 5-HT receptor activation. Chronic administration leads to adaptive downregulation of 5-HT1A autoreceptors, increased serotonergic neurotransmission, and downstream neuroplastic changes including increased brain-derived neurotrophic factor expression. Sertraline also shows sigma-1 receptor agonism and mild inhibition of the dopamine transporter, which may contribute to its efficacy across anxiety, obsessive-compulsive, and trauma-related disorders.
See it in motion
A schematic animation of the mechanism — simplified for clarity, not drawn to scale.
Imagine a whiteboard where messages are written in serotonin.
- Nerve cells in the brain use a chemical called serotonin to pass messages across the tiny gap between cells.
- After serotonin delivers its message, a pump called the serotonin transporter pulls it back into the sending cell.
- Sertraline blocks that pump, so serotonin stays in the gap longer and keeps stimulating the next cell.
- Over several weeks, this steadier serotonin signaling helps lift mood, reduce obsessive thoughts, calm panic, and ease social fear.
Target: Serotonin transporter (SERT)
A membrane pump that recycles serotonin back into the presynaptic neuron; blocking it leaves more serotonin in the synapse to keep signaling.
Approved uses
Approved uses differ by country and change over time. Always follow your local prescribing information.
Approved uses in United States
FDA- Treatment of major depressive disorder
- Treatment of obsessive-compulsive disorder
- Treatment of panic disorder
- Treatment of posttraumatic stress disorder
- Treatment of social anxiety disorder
- Treatment of premenstrual dysphoric disorder
Approved uses in United States
MedlinePlus- Treatment of depression, obsessive-compulsive disorder, panic attacks, posttraumatic stress disorder, social anxiety disorder, and premenstrual dysphoric disorder
Approved uses in United States
NCI- Antidepressant with selective serotonin reuptake inhibitory activity
Official sources
The statements on this page trace back to these records.
- U.S. Food and Drug Administration: sertraline prescribing information
U.S. Food and Drug Administration
- MedlinePlus: sertraline
MedlinePlus, U.S. National Library of Medicine
- National Cancer Institute: sertraline hydrochloride
National Cancer Institute
This page explains how the medicine works — it isn’t the patient leaflet. For anything that applies to you, read the leaflet that came with your medicine or ask your pharmacist.
MedUnfold provides educational content and is not medical advice. Always follow your local prescribing information and healthcare professional.