What Are The Paxil First Week Side Effects?

Kristin Hall

Reviewed by Kristin Hall, FNP

Written by Our Editorial Team

Published 10/09/2022

Updated 10/10/2022

Just about every antidepressant comes with potential side effects. Some side effects can be mild and some can be severe — it all depends on the medication and how your body interacts with it. 

Some medications can cause weight gain or loss, while others may lead to eye pain, breast pain or urinary retention. All of this is to say, antidepressants all have their own specific adverse reactions.

In addition to this, there may be different times when someone is more prone to feeling adverse effects. Such is the case with Paxil. Many people report feeling more side effects during the first week that they start taking this prescription medication. 

Learn why you may experience side effects during the first week of taking Paxil — but first, get a bit more info on this antidepressant. 

You may know Paxil by its generic name, paroxetine. It’s a type of antidepressant called a selective serotonin reuptake inhibitor (SSRI).SSRIs work by boosting the levels of serotonin in your brain. Known as the happy hormone, serotonin is a neurotransmitter connected to depression and anxiety

Paroxetine is most often prescribed to treat major depressive disorder and other depressive disorders such as bipolar disorder. A study found that a daily dose of paroxetine worked better than a placebo when it came to treating people with acute major depression.

A daily dose of this medication can also be used for anxiety disorders like generalized anxiety disorder, panic disorder and panic attacks, obsessive-compulsive disorder in adults and social anxiety disorder. It is also sometimes used to treat a condition called premenstrual dysphoric disorder

In addition to the above medical conditions, paroxetine is sometimes used “off-label” to treat obsessive compulsive disorder and irritable bowel syndrome in children. This means that the medication hasn’t been approved by the U.S. Food and Drug Administration for these conditions but doctors may prescribe it anyway because there’s some evidence it works. 

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When it comes to common side effects, there are a few that are connected to taking Paxil. Usually, people notice them in the first week and then they start to subside. 

The following side effects are most common: 

  • Dizziness

  • Headaches

  • Confusion

  • Sleep issues, like sleepiness or trouble sleeping

  • Constipation

  • Dry mouth

  • Weakness

  • Vomiting

  • Joint pain

  • Heartburn

  • Weight loss or weight gain

  • Sexual side effects like low libido

If you notice adverse effects of paroxetine, bring them up to your healthcare provider so that he or she can keep an eye on them. Whether it’s sexual side effects, weight gain, weight loss, constipation or any of the others, it’s important to note what you experience so you can see if it continues as you take your daily dose. 

In an attempt to avoid the above side effects, you will be started on a lower daily dose, which will be increased slowly. In fact it’s likely that you’ll be started on the lowest dose of paroxetine that can be effective and then slowly work up to the right dose for you.

Generally, your correct dosage is discovered once you start noticing that your mental status has improved and you are experiencing few to no side effects from the medication.

Though rare, there are some more severe side effects of paroxetine you should be on the lookout for. These include chest pain, trouble breathing, pain in one area of the body (such as leg or breast pain), an irregular heartbeat, itchy or dry skin and fainting. 

There is also a risk of serotonin syndrome. Symptoms of serotonin syndrome include restlessness, diarrhea, chest pain, hallucinations, eye pain, nausea and more. You have a higher risk factor for this condition if you take two medications that affect serotonin levels — these types of medications are sometimes called serotonergic drugs because they affect serotonin levels.

If you notice symptoms of serotonin syndrome or any serious adverse reactions, reach out to a healthcare provider for medical advice as soon as you can.

If a healthcare provider suggests paroxetine, make sure you let them know if you are on any other medications so that they can make sure there are no bad interactions. You should also share if you’ve ever had allergic reactions to any medication you have taken previously.

Finally, do not stop taking paroxetine suddenly, because it can cause withdrawal symptoms. You will want to seek out medical advice first — a healthcare provider can wean you off your dosage slowly, so you don’t experience negative effects of paroxetine ceseastion. 

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Paroxetine (and the brand name Paxil) is an antidepressant that is commonly used to treat conditions like major depression, bipolar disorder, panic disorder and panic attacks, generalized anxiety disorder,social anxiety disorder and premenstrual dysphoric disorder.

There are side effects associated with taking a daily dose of this medication. Most people notice them in the first week of taking paroxetine, but those side effects go away as people get used to the medication. Some of the side effects of paroxetine include weight gain or weight loss, headaches, certain sexual side effects and more. 

There are some rare severe side effects, too. They include chest pain and risk of serotonin syndrome. Symptoms of serotonin syndrome include restlessness, eye pain, diarrhea and more. People are more at risk of serotonin syndrome if they are taking two serotonergic drugs — which are medications that increase serotonin levels — at the same time. 

To avoid potential allergic reactions, it’s important to tell your healthcare provider about any previous allergic reactions you’ve had. 

One way to mitigate side effects is to start on a lower daily dose and work with your healthcare provider to find an effective dose from there. 

Whether you’re dealing with bipolar disorder, panic disorder and panic attacks or something else, it’s a good idea to speak with a healthcare provider to see if paroxetine could be a helpful medication for you. Hers offers online consultations that make it easy. 

During your online meeting, you will be able to talk about your mental health condition and if paroxetine could be a good fit. You’ll also be able to ask about what your daily dose would be and what the first week side effects could be. It is also a good idea to discuss the more serious ones, like the risk of serotonin syndrome. From there, you can decide if it’s the right medication for you.

5 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. Paroextine. National Alliance on Mental Illness. Retrieved from
  2. Chu, A., Wadhwa, R., (2021, May 10). Selective Serotonin Reuptake Inhibitors. Stat Pearls. Retrieved from
  3. Barbui, C., Furukawa, T., Cipriani, A., (2008). Effectiveness of paroxetine in the treatment of acute major depression in adults: a systematic re-examination of published and unpublished data from randomized trials. CMAJ. Retrieved from,%25%20CI%200.77%E2%80%930.90).
  4. Paroxetine. Medline Plus. Retrieved from
  5. Serotonin Syndrome. Medline Plus

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.

Kristin Hall, FNP

Kristin Hall is a board-certified Family Nurse Practitioner with decades of experience in clinical practice and leadership. 

She has an extensive background in Family Medicine as both a front-line healthcare provider and clinical leader through her work as a primary care provider, retail health clinician and as Principal Investigator with the NIH

Certified through the American Nurses Credentialing Center, she brings her expertise in Family Medicine into your home by helping people improve their health and actively participate in their own healthcare. 

Kristin is a St. Louis native and earned her master’s degree in Nursing from St. Louis University, and is also a member of the American Academy of Nurse Practitioners. You can find Kristin on LinkedIn for more information.

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