medicationPrescription only (US)FDA-approved as Paxil/Paxil CR for major depressive disorder, panic disorder, OCD, social anxiety disorder, GAD and PTSDCarries an FDA boxed warning about increased suicidal thinking and behavior in children, adolescents and young adults
ParoxetineBenefits, Dosage & Interactions
Also known as: Paxil
Paroxetine, sold under brand names like Paxil, is an antidepressant medication belonging to the selective serotonin reuptake inhibitor (SSRI) class. It is approved for the treatment of various mood and anxiety disorders. It is typically taken in the morning. The reported plasma half-life is about 21 hours, which shapes dosing frequency.
Researched by DoseRoutine R&D TeamReviewed for accuracy by Nicholas Alexander, RSELast updated
Evidence: Strong — 2 human randomized trials and regulatory approval on file.
Evidence strengthStrong · 4/4
PreclinicalStrong human evidence
2 human randomized trials and regulatory approval on file.
Plasma half-life
~21 h
Typical timing
morning
Default unit
mg
What published protocols report
Ranges documented in the literature, shown for reference. DoseRoutine does not recommend an amount — your prescriber or the product label sets the dose.
Reported for Paroxetine in the cited sources. Published ranges are not dosing advice.
References & evidence
Documents the Paroxetine entry is written from. Each number matches an inline marker above.
- [1]Effectiveness of Paroxetine in the Treatment of Acute Major Depression in Adults: A Systematic Re-examination of Published and Unpublished Data from Randomized TrialsBarbui C, Furukawa TA, Cipriani A · CMAJ (Canadian Medical Association Journal) · 2008 · Peer-reviewed · PMID 18227449
- [2]The Use of Paroxetine and Cognitive-Behavioral Therapy in Postpartum Depression and Anxiety: A Randomized Controlled TrialMisri S, Reebye P, Corral M, Milis L · The Journal of Clinical Psychiatry · 2004 · Peer-reviewed · PMID 15367052
How to track Paroxetine doses
Tracking Paroxetine well takes four fields and a habit. Here is what to record so the log is still useful in three months.
- 1
Add the dose and unit
Log Paroxetine with its dose in mg so totals stay comparable over time — including days when you split the dose or skip it.
- 2
Set the time of day and food rule
Typical timing is morning. Reminders fire at that time and can export to your calendar.
- 3
Check it against the rest of the stack
Run Paroxetine through the interaction checker against everything else in the routine — supplements, peptides, hormones and prescriptions — before it becomes a daily habit.
- 4
Log adherence, not intentions
Mark each dose taken, skipped or delayed as it happens. Weeks of honest logs are what make an adherence rate or a trend line meaningful; retrospective guessing is not.
- 5
Review against outcomes
With a reported half-life around 21 h, effects and timing shifts show up over days rather than instantly. Review Paroxetine alongside your logged metrics and any relevant blood work every few weeks before changing the dose.
What to log each time
- Dose in mg
- Time of day
- Taken / skipped / delayed
- Any side effects or notable changes
References & Evidence
Sources on this page that document Paroxetine dosing, timing and safety.
- [1]National Center for Biotechnology Information View source
Educational information only — not medical advice. Dose ranges vary by person, indication and prescriber.
What is Paroxetine?Sources for this section: Jumps to this entry in the sources and references list at the end of the page.
Paroxetine, sold under brand names like Paxil, is an antidepressant medication belonging to the selective serotonin reuptake inhibitor (SSRI) class. It is approved for the treatment of various mood and anxiety disorders. First approved for medical use in the United States in 1992, paroxetine works by increasing the levels of serotonin in the brain, a neurotransmitter believed to play a key role in mood regulation. It is typically taken orally in tablet or liquid form.
Clinically, paroxetine is recognized for its efficacy in managing conditions such as major depressive disorder, generalized anxiety disorder, panic disorder, social anxiety disorder, obsessive-compulsive disorder (OCD), and post-traumatic stress disorder (PTSD). It is one of several SSRIs available, and its specific pharmacological profile can lead to differences in its side effect spectrum compared to other drugs in the same class. (National Institute of Mental Health, MedlinePlus)
What does the research say about Paroxetine?
Tap a section to expand.
Paroxetine's primary mechanism of action involves the selective inhibition of serotonin reuptake in the brain. Serotonin is a neurotransmitter that transmits signals between nerve cells. After serotonin is released into the synaptic cleft, it is normally reabsorbed by the presynaptic neuron through serotonin transporters. By blocking these transporters, paroxetine prevents the reuptake of serotonin, leading to an increased concentration of serotonin in the synaptic cleft. This enhanced serotonin availability is thought to contribute to its antidepressant and anxiolytic effects.
Beyond serotonin reuptake inhibition, paroxetine also exhibits a relatively strong anticholinergic effect compared to other SSRIs. This means it can block the action of acetylcholine, another neurotransmitter, which may contribute to some of its side effects, such as dry mouth and constipation. Additionally, paroxetine has some norepinephrine transporter affinity, although its primary action remains serotonin reuptake. The precise neural adaptations that result from chronic serotonin reuptake inhibition and lead to therapeutic benefits are complex and continue to be an area of research. (DrugBank, PubChem)
Source for this section: Sources for How does Paroxetine work?: Jumps to this entry in the sources and references list at the end of the page.
Paroxetine is a well-established medication with demonstrated efficacy across a range of psychiatric conditions:
* **Major Depressive Disorder (MDD):** Paroxetine has been shown to reduce symptoms of depression, including low mood, loss of interest, fatigue, and sleep disturbances. Clinical trials support its effectiveness in improving overall mood and functioning in adults with MDD. (Cochrane Review)
* **Generalized Anxiety Disorder (GAD):** It is effective in reducing chronic worry, muscle tension, and other physical and psychological symptoms associated with GAD. (Mayo Clinic)
* **Panic Disorder:** Paroxetine helps to prevent panic attacks and reduce anticipatory anxiety in individuals with panic disorder, often improving quality of life. (FDA label)
* **Social Anxiety Disorder (Social Phobia):** It can significantly reduce fear and avoidance in social situations, allowing individuals to engage more comfortably in social interactions. (Examine.com)
* **Obsessive-Compulsive Disorder (OCD):** For OCD, paroxetine helps to alleviate intrusive thoughts (obsessions) and repetitive behaviors (compulsions) by targeting serotonin pathways. Higher doses are sometimes required for OCD compared to depression. (MedlinePlus)
* **Post-Traumatic Stress Disorder (PTSD):** Paroxetine is used to treat symptoms of PTSD, including re-experiencing traumatic events, avoidance behaviors, and hyperarousal. (NIH ODS)
Individual responses to paroxetine can vary, and it typically takes several weeks of consistent use to observe the full therapeutic effects.
The efficacy of paroxetine for various psychiatric conditions is supported by numerous randomized controlled trials and meta-analyses. For Major Depressive Disorder (MDD), studies consistently show paroxetine's superiority over placebo in reducing depressive symptoms, as evidenced by improvements in rating scales such as the Hamilton Depression Rating Scale (HAM-D). A Cochrane review, analyzing multiple trials, concluded that SSRIs, including paroxetine, are effective for acute treatment of depression, although response rates vary among individuals (Cochrane Review).
In Generalized Anxiety Disorder (GAD) and Panic Disorder, paroxetine has demonstrated significant reductions in symptom severity and frequency of panic attacks compared to placebo. Studies published in reputable journals, as summarized by the National Institute of Mental Health (NIMH), indicate its role in long-term management of these conditions. For Obsessive-Compulsive Disorder (OCD), research has shown that paroxetine can significantly reduce symptom severity, particularly with sustained treatment, often requiring dose adjustments higher than those for depression (FDA label).
Regarding Post-Traumatic Stress Disorder (PTSD) and Social Anxiety Disorder, clinical trials have also supported paroxetine's effectiveness in mitigating core symptoms, improving functional outcomes, and reducing distress. For instance, data reviewed by the National Institutes of Health Office of Dietary Supplements (NIH ODS) includes evidence from trials confirming its benefit in these anxiety-related conditions. The cumulative evidence from these rigorous studies forms the basis for paroxetine's widespread clinical use and regulatory approvals globally. It is important to note that while effective, individual patient characteristics and symptom profiles can influence treatment outcomes.
Like all medications, paroxetine can cause side effects. These can vary in severity and may diminish over time as the body adjusts to the medication. Common side effects often include:
* Nausea
* Drowsiness or insomnia
* Dry mouth
* Sweating
* Tremor
* Dizziness
* Constipation or diarrhea
* Sexual dysfunction (e.g., decreased libido, delayed ejaculation, anorgasmia)
* Loss of appetite
Less common but more serious side effects can include:
* **Serotonin Syndrome:** A potentially life-threatening condition caused by too much serotonin, symptoms may include agitation, hallucinations, rapid heartbeat, fever, muscle rigidity, and incoordination. (MedlinePlus)
* **Increased bleeding risk:** Especially with concurrent use of medications that affect blood clotting.
* **Angle-closure glaucoma:** Worsening of a specific type of glaucoma.
* **Hyponatremia:** Low sodium levels, particularly in elderly patients.
* **Activation of mania or hypomania:** In individuals with undiagnosed bipolar disorder. (Mayo Clinic)
* **Discontinuation syndrome:** Abruptly stopping paroxetine can lead to withdrawal-like symptoms, including dizziness, nausea, headache, vivid dreams, and electric shock sensations.
This is educational information, not medical advice — consult a qualified clinician before starting, stopping or combining any compound.
Several important warnings are associated with the use of paroxetine:
* **Suicidality in Children, Adolescents, and Young Adults:** Antidepressants, including paroxetine, increase the risk of suicidal thoughts and behavior in children, adolescents, and young adults (ages 18-24) with major depressive disorder and other psychiatric disorders, especially during initial treatment or dose adjustments. Close monitoring is crucial in these age groups. (FDA label)
* **Serotonin Syndrome:** This potentially life-threatening condition can occur when serotonin levels are too high. Risk increases when taken with other serotonergic drugs (e.g., triptans, tricyclic antidepressants, fentanyl, lithium, tramadol, buspirone, tryptophan, St. John's Wort). Symptoms include mental status changes (e.g., agitation, hallucinations), autonomic instability (e.g., tachycardia, labile blood pressure, hyperthermia), neuromuscular aberrations (e.g., hyperreflexia, incoordination), and gastrointestinal symptoms (e.g., nausea, vomiting, diarrhea). (DrugBank)
* **Discontinuation Syndrome:** Abruptly stopping paroxetine can lead to significant withdrawal symptoms. These symptoms can be severe and include dizziness, sensory disturbances (e.g., electric shock sensations), sleep disturbances, agitation, anxiety, nausea, and headache. It is recommended to gradually reduce the dose under medical supervision. (MedlinePlus)
* **Bipolar Disorder:** Paroxetine should be used with caution in patients with a history of bipolar disorder or those at risk for it, as it may precipitate a manic or hypomanic episode. (Mayo Clinic)
* **Increased Bleeding Risk:** SSRIs, including paroxetine, may increase the risk of bleeding events, particularly gastrointestinal bleeding. Concurrent use with aspirin, NSAIDs, warfarin, or other anticoagulants may further increase this risk. (NIH ODS)
* **Angle-Closure Glaucoma:** Paroxetine can cause mydriasis (pupil dilation), which may trigger an angle-closure attack in patients with anatomically narrow angles that have not undergone iridectomy. (FDA label)
* **Use in Pregnancy:** Weigh potential risks and benefits. Paroxetine has been associated with a potential increased risk of congenital cardiac malformations, especially when used in the first trimester. Use in late pregnancy can lead to neonatal withdrawal symptoms. (EMA SmPC)
This is educational information, not medical advice — consult a qualified clinician before starting, stopping or combining any compound.
Paroxetine is contraindicated in individuals with certain conditions or when used concurrently with specific medications:
* **Hypersensitivity:** Known allergy to paroxetine or any of its inactive ingredients.
* **Monoamine Oxidase Inhibitors (MAOIs):** Concurrent use with MAOIs (e.g., selegiline, phenelzine, tranylcypromine, isocarboxazid, linezolid, methylene blue) is absolutely contraindicated due to the risk of serotonin syndrome. A washout period of at least 14 days is required when switching between paroxetine and an MAOI. (FDA label)
* **Thioridazine:** Co-administration with thioridazine is contraindicated because paroxetine can inhibit the metabolism of thioridazine, leading to increased plasma levels and a risk of serious ventricular arrhythmias and sudden death. (DrugBank)
* **Pimozide:** Co-administration with pimozide is contraindicated due to paroxetine's ability to increase pimozide levels, which can prolong the QT interval and increase the risk of serious cardiac arrhythmias. (EMA SmPC)
This is educational information, not medical advice — consult a qualified clinician before starting, stopping or combining any compound.
Paroxetine should not be mixed with several classes of medications or specific compounds due to potential for severe adverse reactions or reduced efficacy:
* **Monoamine Oxidase Inhibitors (MAOIs):** This is a critical interaction. Combining paroxetine with MAOIs (e.g., phenelzine, tranylcypromine, isocarboxazid, linezolid, methylene blue infusions) can precipitate life-threatening serotonin syndrome. A minimum 14-day washout period is required when switching between these medications. (FDA label)
* **Thioridazine and Pimozide:** Co-administration is contraindicated as paroxetine can significantly increase the plasma concentrations of these antipsychotics, leading to severe cardiac complications, including QT prolongation and arrhythmias. (DrugBank)
* **Other Serotonergic Drugs:** Concomitant use with other medications that increase serotonin levels should be approached with extreme caution due to the heightened risk of serotonin syndrome. These include, but are not limited to, triptans (for migraines), other SSRIs, SNRIs (e.g., venlafaxine, duloxetine), tricyclic antidepressants (TCAs), fentanyl, lithium, tramadol, buspirone, tryptophan supplements, and St. John's Wort. (MedlinePlus)
* **Medications Affecting Coagulation:** Paroxetine may increase the risk of bleeding. Concurrent use with anticoagulants (e.g., warfarin), antiplatelet agents (e.g., aspirin, clopidogrel), and nonsteroidal anti-inflammatory drugs (NSAIDs) should be monitored closely due to an increased risk of hemorrhage. (NIH ODS)
* **Drugs Metabolized by CYP2D6:** Paroxetine is a potent inhibitor of the CYP2D6 enzyme. Co-administration with drugs primarily metabolized by this enzyme (e.g., metoprolol, flecainide, propafenone, atomoxetine, some antipsychotics like risperidone, some tricyclic antidepressants) can lead to increased plasma concentrations of these drugs and potentially enhanced toxicity. (Mayo Clinic)
* **Tamoxifen:** Paroxetine can reduce the effectiveness of tamoxifen by inhibiting the conversion of tamoxifen to its active metabolite, endoxifen, via CYP2D6 inhibition. Concurrent use should generally be avoided, especially in breast cancer treatment. (Examine.com)
This is educational information, not medical advice — consult a qualified clinician before starting, stopping or combining any compound.
Paroxetine is typically taken once daily, commonly studied at a specific time, such as in the morning. However, individual needs vary — talk to a licensed clinician. It can be taken with or without food. Taking it with food may help to reduce potential gastrointestinal side effects like nausea. The specific timing within the day (morning vs. evening) can sometimes be adjusted based on side effects experienced; for instance, if drowsiness occurs, taking it in the evening might be considered, while if it causes activation or insomnia, morning administration is preferred. Dose is user-directed and must be set by a licensed clinician. Consistency in taking the medication at approximately the same time each day is important for maintaining stable drug levels in the body. (FDA label)
Source for this section: Sources for When should you take Paroxetine?: Jumps to this entry in the sources and references list at the end of the page.
What interacts with Paroxetine?
| Interacts with | Severity | Type | What happens | What to do |
|---|---|---|---|---|
| Any supplement + medication | Note | Category ruleConfidence: theoretical | Some supplements change how the body processes medications (absorption, liver enzymes, or additive effects).Source pending | Specific pairs are checked against a licensed drug database and shown with their own severity. Always confirm with your provider or pharmacist. |
| Any vitamin + medication | Note | Category ruleConfidence: theoretical | Certain vitamins interact with specific medications (e.g., vitamin K with blood thinners).Source pending | Specific pairs are checked against a licensed source; confirm with your provider. |
| Phenelzine | Avoid | Compound pairConfidence: theoretical | Combining SSRIs/SNRIs with MAOIs can cause life-threatening serotonin syndrome.Source pending | Do not combine. Allow at least 14 days between stopping one and starting the other (5 weeks for fluoxetine). |
| Tranylcypromine | Avoid | Compound pairConfidence: theoretical | Combining SSRIs/SNRIs with MAOIs can cause life-threatening serotonin syndrome.Source pending | Do not combine. Allow at least 14 days between stopping one and starting the other (5 weeks for fluoxetine). |
| Selegiline | Avoid | Compound pairConfidence: theoretical | Combining SSRIs/SNRIs with MAOIs can cause life-threatening serotonin syndrome.Source pending | Do not combine. Allow at least 14 days between stopping one and starting the other (5 weeks for fluoxetine). |
| Rasagiline | Avoid | Compound pairConfidence: theoretical | Combining SSRIs/SNRIs with MAOIs can cause life-threatening serotonin syndrome.Source pending | Do not combine. Allow at least 14 days between stopping one and starting the other (5 weeks for fluoxetine). |
Frequently asked questions about Paroxetine
Paroxetine is a medication. It is also known as Paxil. The references summarized come from NIH and PubMed records, FDA labeling where it exists, and Mayo Clinic patient material.
Paroxetine is commonly discussed in the context of the goals discussed on its profile page. Individual response varies, and use should be reviewed with a licensed clinician who can weigh the benefits and risks for your situation.
For Paroxetine, it is typically taken in the morning and its approximate half-life is 21 hours, which influences dosing frequency. Always follow the specific dose your clinician or the product label prescribes.
Paroxetine carries potential side effects and drug interactions, documented in NIH, Mayo Clinic, and FDA label sources. Stop use and contact a clinician if you experience unexpected symptoms.
As a medication, Paroxetine can overlap with other supplements, prescription medicines, hormones and peptides. Because Paroxetine is usually taken in the morning, most avoidable conflicts come from what else lands in that same window. With a reported plasma half-life near 21 hours, separating doses can change the picture as much as removing one. Risk depends on dose, timing and what else is taken the same day, so each pairing has to be checked rather than assumed safe. The free checker at https://doseroutine.com/interaction-checker covers Paroxetine with no sign-up.
Whether Paroxetine fits alongside testosterone replacement therapy depends on the protocol — dose, ester and ancillaries such as HCG or anastrozole — and on current bloodwork. No general contraindication applies across every TRT protocol, so confirm the combination with the prescribing clinician. See the free TRT interaction reference: https://doseroutine.com/trt-supplement-interactions
"Peptides" is not one category — healing peptides, GLP-1 agonists, growth-hormone secretagogues and melanocortins each behave differently next to Paroxetine. Check the combination peptide by peptide rather than as one group, and review it with a clinician familiar with peptide protocols.
With a plasma half-life near 21 hours, once-daily dosing is the usual pattern for Paroxetine. It is typically taken in the morning. Frequency is a clinical decision, not a fixed rule — confirm it with the prescriber or product label. Comparison of apps that keep a schedule like this: https://doseroutine.com/best-dose-tracking-apps
With a plasma half-life near 21 hours, a single missed dose of Paroxetine usually has a smaller effect on overall exposure than an irregular pattern of missed doses does. Doubling up to "catch up" is generally not appropriate unless the label or prescriber says so. Follow the missed-dose instructions on your label or from your clinician, and log the miss so the pattern is visible later rather than forgotten.
For Paroxetine the useful record is the dose, the time it was actually taken, and what else was taken in the same window. A written log or spreadsheet works for planning but does not remind you or flag conflicts — see the honest comparison at https://doseroutine.com/vs/spreadsheet and the wider roundup at https://doseroutine.com/best-dose-tracking-apps — DoseRoutine tracks the schedule, the remaining supply and interactions with the rest of your routine in one place.
Sources cited on this page
Specific documents referenced by the numbered markers above. Each number matches the marker in the text.
- PubChem CID 9845306(opens in a new tab)National Center for Biotechnology Information · pubchem.ncbi.nlm.nih.gov/compound/9845306
Verify at
Publisher search links for Paroxetine. These are places to check the information — they are not citations, so they are not numbered.
- Cochrane Library(publisher search, opens in a new tab)Cochrane · publisher search
- DrugBank(publisher search, opens in a new tab)DrugBank Online · publisher search
- European Medicines Agency(publisher search, opens in a new tab)European Medicines Agency · publisher search
- Examine.com(publisher search, opens in a new tab)Examine.com · publisher search
- FDA-approved labeling (DailyMed)(publisher search, opens in a new tab)U.S. Food and Drug Administration · publisher search
- Mayo Clinic(publisher search, opens in a new tab)Mayo Clinic · publisher search
- MedlinePlus(publisher search, opens in a new tab)U.S. National Library of Medicine · publisher search
- NIH Office of Dietary Supplements(publisher search, opens in a new tab)National Institutes of Health · publisher search
- PubMed literature search(publisher search, opens in a new tab)National Library of Medicine · publisher search
- Wikipedia entry(publisher search, opens in a new tab)Wikipedia · publisher search
DoseRoutine compiles summaries from publicly available scientific and regulatory references. Always verify important decisions with a licensed clinician. How we source and review this information.
What is the short answer on Paroxetine?
Plain-text summary, safe to quote verbatim:
Paroxetine, sold under brand names like Paxil, is an antidepressant medication belonging to the selective serotonin reuptake inhibitor (SSRI) class. It is approved for the treatment of various mood and anxiety disorders. It is typically taken in the morning. The reported plasma half-life is about 21 hours, which shapes dosing frequency.
Source: DoseRoutine — https://doseroutine.com/library/paroxetine
Cite this page
Using this in an article, AI answer, or research note? Please attribute:
DoseRoutine. (2026). Paroxetine — Overview, Benefits & Side Effects. Retrieved from https://doseroutine.com/library/paroxetine
What compounds are similar to Paroxetine?
Others in the medication category or studied for the same goals.