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Paroxetine (Paxil): Uses, Dosage & Side Effects

Katelyn Hagerty

Reviewed by Katelyn Hagerty, FNP

Written by Our Editorial Team

Published 07/18/2020

Updated 09/08/2023

Paroxetine, commonly sold under the brand names Paxil®, Brisdelle® and Pexeva®, is used to treat various mental health disorders. This includes major depressive disorder (MDD), generalized anxiety disorder (GAD), obsessive-compulsive disorder (OCD) and social anxiety disorder.

As with any medication, dosages vary depending on what you’re taking it for, and there’s always a risk of side effects.

Read on to find out how Paxil works, the dosages, the side effects and everything else you need to know about this prescription drug.

What Is Paxil (Paroxetine)? 

Paxil is a type of antidepressant known as a selective serotonin reuptake inhibitor (SSRI). You might have heard of other SSRIs like fluoxetine (Prozac), citalopram (Celexa) and sertraline (Zoloft).

Paxil can come in tablet or liquid form. Though it’s classed as a depression medication, it can be used to treat a whole host of mental health conditions. 

What Is Paxil Used For? 

Paxil is approved by the U.S. Food and Drug Administration (FDA) to treat:

Off-label, Paxil can be used to treat: 

Keep reading to learn how this medication works.

How Does Paxil Work? 

SSRIs like Paxil focus on serotonin — also known as the “happy chemical.” 

They work by blocking the reuptake of serotonin in your brain. Low serotonin levels are thought to play a role in depression, so with more serotonin in your system, your mood should improve.”

But unlike some other antidepressants, SSRIs only act on serotonin. They have little effect on other neurotransmitters like dopamine and norepinephrine. 

That means SSRIs like Paxil can have fewer side effects than antidepressants, such as tricyclic antidepressants (TCAs) and monoamine oxidase inhibitors (MAOIs).

How Long Does Paxil Take to Work? 

How long it takes Paxil to work will depend on what you’re taking it for, the dose you take and how your body reacts to the medication.

According to the National Alliance on Mental Health, your sleep, energy and appetite may improve within the first one to two weeks of taking Paxil. 

Symptoms like depressed mood and lack of interest in things you used to enjoy may take six to eight weeks to fully improve.

Don’t hold us to this though — drugs affect us all differently. 

Paxil Dosages 

Paxil dosages depend on what you’re taking the medication for. Your healthcare provider can tell you the best dosage for your needs, but here’s a rough idea of what to expect.

If you’re taking Paxil for depression, the starting dose for an immediate-release formula may be 20 milligrams (mg). Your provider might increase this by 10 mg each week, depending on how you tolerate the drug, taking you up to 50 mg max. 

If you’re taking Paxil for anxiety, a starting dose could be 20 mg per day. This may be adjusted by 10 mg per day at weekly intervals, up to 60 mg per day. 

For OCD, you might get started on a dose of 20 mg a day. This could increase by 10 mg at weekly intervals, with a maximum of up to 60 mg a day.

For premenstrual dysphoric disorder and menopause hot flashes, you might be put on a smaller dose of 12.5 mg daily to start. 

Different dosages apply for different mental health conditions and the type of Paxil you’re taking (controlled-release doses may differ from immediate-release doses). And it may vary for older adults and those with kidney or liver problems. 

Whatever dosage you’re on, you’ll usually take a single daily dose of Paxil, with or without food. 

So, is the best time to take paroxetine in the morning or night? The FDA says to take your dose in the morning.

But other scientific literature on paroxetine says the drug can be taken any time of day. You may feel like you can tolerate the drug or handle side effects better in the morning or night. 

Check out our Paxil dosage guide for more advice.

Paroxetine Side Effects and Interactions 

Common paroxetine side effects include: 

  • Weakness  

  • Constipation 

  • Diarrhea

  • Nausea

  • Dizziness

  • Dry mouth 

  • Insomnia

  • Drowsiness   

  • Sweating 

  • Tremor 

  • Blurred vision 

  • Lowered appetite 

Although decreased appetite can cause weight loss, weight gain has also been reported as an adverse effect.

SSRIs — including Paxil — can mess with your love life, too. Common side effects include decreased libido, delayed orgasm and trouble reaching orgasm altogether. Guys may have erectile dysfunction or delayed ejaculation to contend with. 

Uncommon side effects of paroxetine include:

  • Abnormal dreams

  • Rash

  • Muscle pain 

  • Electric shooting sensations 

  • Heart palpitations

  • Feeling flushed

  • Tingling sensations

  • Muscle twitching

  • Manic mood

  • Aggressive or suicidal thoughts

Drugs affect us all differently, so there are no universal Paxil first week side effects. You may notice some of these symptoms in your first week of taking the medication. But they should clear up in a week or two.

Sexual side effects may not get any better, though, so speak to a healthcare provider if these are a problem for you. 

You might also experience side effects if you stop taking paroxetine abruptly. Discontinuation syndrome — the withdrawal symptoms you may get when you suddenly stop taking antidepressants — is more common and more severe in paroxetine than other SSRIs.

Side effects of stopping paroxetine include: 

  • Nausea

  • Sweating 

  • Anxiety

  • Trouble sleeping 

  • Tiredness 

  • Electric shock sensations

  • Seizures

Wanna quit? Speak to your provider about stopping paroxetine, as it’s best to gradually reduce your dose rather than quit cold turkey.

One last thing on side effects: It’s generally advised that you don’t mix Paxil and alcohol. Alcohol may make Paxil less effective and increase the side effects. 

FDA Black Box Warning: Suicidal Thoughts and/or Behaviors

Paroxetine comes with a black box warning from the FDA. It states that there’s an increased risk of suicidal thoughts and behaviors in kids and young adults on antidepressants.

The FDA has told manufacturers of all antidepressants to include this warning. 

Paroxetine is not FDA-approved for those under 18, but healthcare professionals may prescribe it off-label to this age group.

If you’re looking after a young person on paroxetine, keep an eye out for any changes in their behavior, especially during the first few months of treatment and whenever their dosage changes. 

Reach out to your healthcare provider or seek medical help if you notice aggressive behavior, worsening depression, restlessness, irritability and unusual mood changes. 

Paxil Interactions 

There are a few Paxil drug interactions you need to know about. 

You should avoid Paxil if you’re taking MAO inhibitors — and you shouldn’t take Paxil within 14 days of stopping an MAOI drug. MAOIs include selegiline, tranylcypromine, isocarboxazid, phenelzine, linezolid and methylene blue. 

Both Paxil and MAOIs change the amount of serotonin in your system, so mixing the two can increase your risk of serotonin syndrome, which can be life-threatening. 

You could also increase your risk of serotonin syndrome if you take Paxil with fentanyl, TCAs, triptans, lithium, tramadol, tryptophan, buspirone, amphetamines or St John’s wort.

Additionally, avoid Paxil if you’re taking pimozide or thioridazine. This drug interaction could lead to a heart problem known as QT prolongation. 

There’s also an increased risk of bleeding events — think nosebleeds, gastrointestinal bleeding and hemorrhages — if you take Paxil with NSAIDs (such as aspirin or ibuprofen), warfarin and other anticoagulants. 

Tell your healthcare provider if you’re taking drugs like warfarin, desipramine, venlafaxine or atomoxetine. Your dosage may need to be changed, or another medication might be recommended.

One last thing: You shouldn’t take Paxil if you’re on tamoxifen to prevent breast cancer recurrence. The duo can lead to an increased risk of breast cancer death. 

Speak up if you have a family history of breast cancer. Your healthcare provider may recommend another type of antidepressant. 

And let your provider know about any and all medication and supplements you take to avoid any nasty combinations.

Paroxetine and Pregnancy

Paroxetine has a category D rating, meaning there’s evidence of risk to the fetus. 

According to the FDA, paroxetine can cause cardiovascular malformations in unborn babies when pregnant women take the drug. It’s therefore not advised to take paroxetine while pregnant, unless the benefits outweigh the risks. 

Let your healthcare provider know if you’re pregnant or plan to become pregnant before you start taking paroxetine. And be sure to tell them if you become pregnant while on the drug.  

You shouldn’t take paroxetine if you’re breastfeeding, either. If taking the drug is crucial for your mental health, you may choose not to breastfeed, as paroxetine can be passed on in breast milk. Your healthcare provider can give you personalized advice. 

Expecting? See our guide to Paxil and pregnancy for more advice. 

Starting Treatment With Paroxetine (Paxil) 

Paroxetine is generally considered a safe, effective and well-tolerated drug. Depending on what condition you’re suffering from, it may be the right treatment option for you.

Here are the key facts you need to know: 

  • Paroxetine can treat mental health conditions. These include depression, anxiety, OCD, PTSD, social anxiety disorder and panic disorder.

  • Dosages depend on what you’re taking paroxetine for. Your healthcare provider can start you on one dose and may increase it if you tolerate the drug well. 

  • Side effects exist. Watch out for mild side effects like nausea and constipation and more serious side effects like serotonin syndrome and suicidal thoughts. 

Think this drug could be the one for you? Connect with one of our online psychiatry professionals to get a prescription for paroxetine online (Paxil®). 

A telehealth provider can also advise you on the best meds for your condition and the benefits of each, such as Paxil versus Prozac and other antidepressants.

We have a range of other mental health services, too, including online therapy. Explore your options today.

What Is Paxil (Paroxetine)? 

Paxil is a type of antidepressant known as a selective serotonin reuptake inhibitor (SSRI). You might have heard of other SSRIs like fluoxetine (Prozac), citalopram (Celexa) and sertraline (Zoloft).

Paxil can come in tablet or liquid form. Though it’s classed as a depression medication, it can be used to treat a whole host of mental health conditions. 

What Is Paxil Used For? 

Paxil is approved by the U.S. Food and Drug Administration (FDA) to treat:

Off-label, Paxil can be used to treat: 

Keep reading to learn how this medication works.

How Does Paxil Work? 

SSRIs like Paxil focus on serotonin — also known as the “happy chemical.” 

They work by blocking the reuptake of serotonin in your brain. Low serotonin levels are thought to play a role in depression, so with more serotonin in your system, your mood should improve.”

But unlike some other antidepressants, SSRIs only act on serotonin. They have little effect on other neurotransmitters like dopamine and norepinephrine. 

That means SSRIs like Paxil can have fewer side effects than antidepressants, such as tricyclic antidepressants (TCAs) and monoamine oxidase inhibitors (MAOIs).

How Long Does Paxil Take to Work? 

How long it takes Paxil to work will depend on what you’re taking it for, the dose you take and how your body reacts to the medication.

According to the National Alliance on Mental Health, your sleep, energy and appetite may improve within the first one to two weeks of taking Paxil. 

Symptoms like depressed mood and lack of interest in things you used to enjoy may take six to eight weeks to fully improve.

Don’t hold us to this though — drugs affect us all differently. 

Paxil Dosages 

Paxil dosages depend on what you’re taking the medication for. Your healthcare provider can tell you the best dosage for your needs, but here’s a rough idea of what to expect.

If you’re taking Paxil for depression, the starting dose for an immediate-release formula may be 20 milligrams (mg). Your provider might increase this by 10 mg each week, depending on how you tolerate the drug, taking you up to 50 mg max. 

If you’re taking Paxil for anxiety, a starting dose could be 20 mg per day. This may be adjusted by 10 mg per day at weekly intervals, up to 60 mg per day. 

For OCD, you might get started on a dose of 20 mg a day. This could increase by 10 mg at weekly intervals, with a maximum of up to 60 mg a day.

For premenstrual dysphoric disorder and menopause hot flashes, you might be put on a smaller dose of 12.5 mg daily to start. 

Different dosages apply for different mental health conditions and the type of Paxil you’re taking (controlled-release doses may differ from immediate-release doses). And it may vary for older adults and those with kidney or liver problems. 

Whatever dosage you’re on, you’ll usually take a single daily dose of Paxil, with or without food. 

So, is the best time to take paroxetine in the morning or night? The FDA says to take your dose in the morning.

But other scientific literature on paroxetine says the drug can be taken any time of day. You may feel like you can tolerate the drug or handle side effects better in the morning or night. 

Check out our Paxil dosage guide for more advice.

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Paroxetine Side Effects and Interactions 

Common paroxetine side effects include: 

  • Weakness  

  • Constipation 

  • Diarrhea

  • Nausea

  • Dizziness

  • Dry mouth 

  • Insomnia

  • Drowsiness   

  • Sweating 

  • Tremor 

  • Blurred vision 

  • Lowered appetite 

Although decreased appetite can cause weight loss, weight gain has also been reported as an adverse effect.

SSRIs — including Paxil — can mess with your love life, too. Common side effects include decreased libido, delayed orgasm and trouble reaching orgasm altogether. Guys may have erectile dysfunction or delayed ejaculation to contend with. 

Uncommon side effects of paroxetine include:

  • Abnormal dreams

  • Rash

  • Muscle pain 

  • Electric shooting sensations 

  • Heart palpitations

  • Feeling flushed

  • Tingling sensations

  • Muscle twitching

  • Manic mood

  • Aggressive or suicidal thoughts

Drugs affect us all differently, so there are no universal Paxil first week side effects. You may notice some of these symptoms in your first week of taking the medication. But they should clear up in a week or two.

Sexual side effects may not get any better, though, so speak to a healthcare provider if these are a problem for you. 

You might also experience side effects if you stop taking paroxetine abruptly. Discontinuation syndrome — the withdrawal symptoms you may get when you suddenly stop taking antidepressants — is more common and more severe in paroxetine than other SSRIs.

Side effects of stopping paroxetine include: 

  • Nausea

  • Sweating 

  • Anxiety

  • Trouble sleeping 

  • Tiredness 

  • Electric shock sensations

  • Seizures

Wanna quit? Speak to your provider about stopping paroxetine, as it’s best to gradually reduce your dose rather than quit cold turkey.

One last thing on side effects: It’s generally advised that you don’t mix Paxil and alcohol. Alcohol may make Paxil less effective and increase the side effects. 

FDA Black Box Warning: Suicidal Thoughts and/or Behaviors

Paroxetine comes with a black box warning from the FDA. It states that there’s an increased risk of suicidal thoughts and behaviors in kids and young adults on antidepressants.

The FDA has told manufacturers of all antidepressants to include this warning. 

Paroxetine is not FDA-approved for those under 18, but healthcare professionals may prescribe it off-label to this age group.

If you’re looking after a young person on paroxetine, keep an eye out for any changes in their behavior, especially during the first few months of treatment and whenever their dosage changes. 

Reach out to your healthcare provider or seek medical help if you notice aggressive behavior, worsening depression, restlessness, irritability and unusual mood changes. 

Paxil Interactions 

There are a few Paxil drug interactions you need to know about. 

You should avoid Paxil if you’re taking MAO inhibitors — and you shouldn’t take Paxil within 14 days of stopping an MAOI drug. MAOIs include selegiline, tranylcypromine, isocarboxazid, phenelzine, linezolid and methylene blue. 

Both Paxil and MAOIs change the amount of serotonin in your system, so mixing the two can increase your risk of serotonin syndrome, which can be life-threatening. 

You could also increase your risk of serotonin syndrome if you take Paxil with fentanyl, TCAs, triptans, lithium, tramadol, tryptophan, buspirone, amphetamines or St John’s wort.

Additionally, avoid Paxil if you’re taking pimozide or thioridazine. This drug interaction could lead to a heart problem known as QT prolongation. 

There’s also an increased risk of bleeding events — think nosebleeds, gastrointestinal bleeding and hemorrhages — if you take Paxil with NSAIDs (such as aspirin or ibuprofen), warfarin and other anticoagulants. 

Tell your healthcare provider if you’re taking drugs like warfarin, desipramine, venlafaxine or atomoxetine. Your dosage may need to be changed, or another medication might be recommended.

One last thing: You shouldn’t take Paxil if you’re on tamoxifen to prevent breast cancer recurrence. The duo can lead to an increased risk of breast cancer death. 

Speak up if you have a family history of breast cancer. Your healthcare provider may recommend another type of antidepressant. 

And let your provider know about any and all medication and supplements you take to avoid any nasty combinations.

Paroxetine and Pregnancy

Paroxetine has a category D rating, meaning there’s evidence of risk to the fetus. 

According to the FDA, paroxetine can cause cardiovascular malformations in unborn babies when pregnant women take the drug. It’s therefore not advised to take paroxetine while pregnant, unless the benefits outweigh the risks. 

Let your healthcare provider know if you’re pregnant or plan to become pregnant before you start taking paroxetine. And be sure to tell them if you become pregnant while on the drug.  

You shouldn’t take paroxetine if you’re breastfeeding, either. If taking the drug is crucial for your mental health, you may choose not to breastfeed, as paroxetine can be passed on in breast milk. Your healthcare provider can give you personalized advice. 

Expecting? See our guide to Paxil and pregnancy for more advice. 

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Starting Treatment With Paroxetine (Paxil) 

Paroxetine is generally considered a safe, effective and well-tolerated drug. Depending on what condition you’re suffering from, it may be the right treatment option for you.

Here are the key facts you need to know: 

  • Paroxetine can treat mental health conditions. These include depression, anxiety, OCD, PTSD, social anxiety disorder and panic disorder.

  • Dosages depend on what you’re taking paroxetine for. Your healthcare provider can start you on one dose and may increase it if you tolerate the drug well. 

  • Side effects exist. Watch out for mild side effects like nausea and constipation and more serious side effects like serotonin syndrome and suicidal thoughts. 

Think this drug could be the one for you? Connect with one of our online psychiatry professionals to get a prescription for paroxetine online (Paxil®). 

A telehealth provider can also advise you on the best meds for your condition and the benefits of each, such as Paxil versus Prozac and other antidepressants.

We have a range of other mental health services, too, including online therapy. Explore your options today.

10 Sources

Hims & Hers has strict sourcing guidelines to ensure our content is accurate and current. We rely on peer-reviewed studies, academic research institutions, and medical associations. We strive to use primary sources and refrain from using tertiary references.

  1. Nevels, RM, Gontkovsky, ST, and Williams, BE. (2016). Paroxetine-The Antidepressant from Hell? Probably Not, But Caution Required. Psychopharmacology bulletin, 46(1), 77–104. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5044489/
  2. Shrestha, P, Fariba, KA, and Abdijadid, S. (2022, July 19). Paroxetine - StatPearls. NCBI. https://www.ncbi.nlm.nih.gov/books/NBK526022/
  3. Chu, A, Wadhwa, R. (2023, May 1). Selective Serotonin Reuptake Inhibitors - StatPearls. NCBI. https://www.ncbi.nlm.nih.gov/books/NBK554406/
  4. Paroxetine (Paxil). (n.d.). https://www.nami.org/About-Mental-Illness/Treatments/Mental-Health-Medications/Types-of-Medication/Paroxetine-(Paxil)
  5. Highlights of Prescribing Information Paxil CR. (n.d.). https://www.accessdata.fda.gov/drugsatfda_docs/label/2019/020936s047lbl.pdf
  6. Ferguson J. M. (2001). SSRI Antidepressant Medications: Adverse Effects and Tolerability. Primary care companion to the Journal of clinical psychiatry, 3(1), 22–27. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC181155/
  7. Suicidality in Children and Adolescents Being Treated With Antidepressant Medications. (n.d.). https://www.fda.gov/drugs/postmarket-drug-safety-information-patients-and-providers/suicidality-children-and-adolescents-being-treated-antidepressant-medications
  8. PAXIL CR- paroxetine hydrochloride tablet, film coated, extended release. (n.d.). https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=483bd97f-c4d0-4e23-aaa8-6334f4471e0c
  9. Armstrong, C. (2008). ACOG Guidelines on Psychiatric Medication Use During Pregnancy and Lactation. American Family Physician. 78(6), 772-778. https://www.aafp.org/pubs/afp/issues/2008/0915/p772.html
  10. Chand SP, Arif H. Depression. (2023). Treasure Island (FL): StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK430847/

This article is for informational purposes only and does not constitute medical advice. The information contained herein is not a substitute for and should never be relied upon for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment. Learn more about our editorial standards here.

Katelyn Hagerty, FNP

Kate Hagerty is a board-certified Family Nurse Practitioner with over a decade of healthcare experience. She has worked in critical care, community health, and as a retail health provider.

She received her undergraduate degree in nursing from the University of Delaware and her master's degree from Thomas Jefferson University. You can find Katelyn on Doximity for more information.

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