Drug vs Drug

Paxil vs Prozac:
Which Is Better For Me?

Learn about the differences between Paxil and Prozac and how to choose the right antidepressant treatment. 
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Paxil vs Prozac

Conflicts, work obligations and daily stresses can take a toll on our mental health, leading to problems like depression and anxiety. If you struggle with mental wellness, it’s important to seek treatment — otherwise, the issue can worsen over time.

One of the most popular treatments for mental health conditions is antidepressants. In this guide, we’ll compare two commonly prescribed antidepressants: Prozac versus Paxil (or paroxetine vs. fluoxetine). Read on to learn more about their differences, their similarities and how DNA testing can help you choose the right medication.

Paxil vs. Prozac: What Are They?

Paxil and Prozac belong to a class of drugs known as antidepressants. Paxil is the branded version of paroxetine, while Prozac is the branded version of fluoxetine. Although they’re two different drugs, they function similarly — both are selective serotonin reuptake inhibitors (SSRIs), which improve mood by increasing serotonin levels. A neurotransmitter found in the brain, serotonin can affect the following:

  • Emotions
  • Appetite
  • Sleep


Paxil and Prozac are available to adults over the age of 18 and can be used to improve mood, satisfaction and overall health.

Paxil vs Prozac for Depression

Depression is a mood disorder associated with consistent, overwhelming sadness and melancholy. Common depression symptoms include:

  • A loss of interest in previously enjoyable activities
  • Difficulty concentrating on things
  • Problems with appetite and digestion
  • Difficulty falling asleep


During depression, the brain produces fewer neurotransmitters. By increasing serotonin levels, Paxil and Prozac can restore these chemical imbalances and consequently reduce negative symptoms.

Paxil vs. Prozac for Anxiety

Anxiety is a mental disorder largely recognized by persistent, intense worry. It can be broken down into the following categories:

  • Generalized anxiety: Excessive worrying in daily situations
  • Panic disorder: Intense episodes of fear/worry
  • Social anxiety disorder: Excessive worrying in social situations
  • Post-traumatic stress disorder (PTSD): Intense fear triggered by a previous traumatic event
  • Obsessive-compulsive disorder (OCD): Uncontrollable, persistent thoughts and behaviors


While these conditions are all different, they share many anxiety symptoms (including restlessness, fatigue and trembling). Like with depression, anxiety can change the levels of neurotransmitters in your brain. This imbalance can be fixed with the aid of medication like SSRIs.

While both Paxil and Prozac provide quick relief of anxiety symptoms, Paxil is more commonly used for this disorder. Paxil is often prescribed to treat all types of anxiety, while Prozac is mainly used in cases of OCD.

Paxil vs Prozac: Dosage Amounts

Since Paxil (paroxetine) and Prozac (fluoxetine) are both SSRIs, it’s common to assume they are interchangeable treatment options. In reality, these drugs have different dosage requirements that would make it dangerous to swap them. The chart below demonstrates how they differ in terms of dosages.

Recommended starting dosage Amount of time for drug to absorb in body Dosage forms
Paxil 20 mg/day (up to 50 mg) 2 – 8 hours Tablet, extended-release tablet, oral solution
Prozac 20 mg/day (up to 40 mg) 4 – 8 hours Tablet, delayed-release tablet, oral solution
Ultimately, Prozac is slightly more potent than Paxil, which is why it has a lower maximum dosage. It can also take longer to absorb in the body (especially if you take the delayed-release tablet).

Paxil vs. Prozac: Side Effects

One of the most important factors to consider during drug selection is side effects. Both Paxil and Prozac may cause the following:

  • Fatigue and lack of energy
  • Decreased libido/sexual side effects
  • Dry mouth and nausea
  • Constipation and diarrhea
  • Lower appetite and weight changes


Both drugs also have their own side effects. For instance, some Paxil users experience muscle pain (which is rare when taking Prozac). On the flip side, Prozac is more likely to cause insomnia (due to its stimulating effects).

There are several reasons why one might be at a higher risk of experiencing side effects, such as age, environment and lifestyle habits. However, the biggest indicator has to do with genetics. If you metabolize certain drugs slowly, they’ll be left in your system for longer periods of time, leading to adverse effects. Fortunately, you can predict this response with pharmacogenetic testing.

ClarityX: Trying DNA Testing Today!

Pharmacogenetic testing, or DNA testing, examines genes for variations that affect how you break down certain medications. Not only does this information help you pick between drugs, but it also helps determine the optimal dosage. At ClarityX, we offer two types of tests:

Once you request your test and complete the check-out process, you can receive and activate your very own kit. Complete the at-home cheek swab, send in the results and get personalized results that will guide your future health decisions!

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