Drug vs Drug

Celexa vs Prozac: Which Is Better?


Learn more about the differences between Celexa (citalopram) and Prozac (fluoxetine) and how to choose the best medication for your needs.

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Celexa vs Prozac

As mental health awareness increases, more and more people are seeking treatment through antidepressants (a class of drugs that can relieve symptoms of depression, anxietyADHD and other mental wellness conditions). When prescribing these medications, doctors have plenty of options to choose from — unfortunately, this can make drug selection difficult.

To help patients better understand their treatment options, this guide examines two well-known antidepressants: Celexa (citalopram) and Prozac (fluoxetine). We’ll cover Celexa vs. Prozac for anxiety and depression, their respective dosages and side effects and how a DNA test can help you choose between them.

Citalopram vs Fluoxetine

Citalopram is a selective serotonin reuptake inhibitor (SSRI) that influences mood and emotions by adjusting the levels of serotonin (a chemical messenger) in the brain. Citalopram is the generic name of the drug, while Celexa is a branded version.

Like citalopram, fluoxetine is an SSRI. It’s available in different branded versions, the most well-known one being Prozac. By increasing serotonin, both drugs can effectively treat conditions characterized by poor mood (like depression and anxiety).

Celexa vs Prozac For Depression

Depression is a serious mood disorder that can grow over time and negatively impact all aspects of life. It’s recognizable through the following symptoms:

  • Loss of interest in hobbies/activities
  • Persistent feelings of sadness
  • Mood swings and irritability
  • Difficulty concentrating
  • Trouble sleeping
  • Appetite problems


In addition to stabilizing the mood, serotonin can assist with sleep and appetite. Thus, both citalopram and fluoxetine have proven effective in lowering depression symptoms.

Celexa vs Prozac For Anxiety

Anxiety is a mental health condition that leads to intense, excessive worrying in everyday life. It can be identified by the following symptoms:

  • Nervousness and restlessness
  • Increased heartbeat
  • Rapid breathing
  • Sweating and shaking
  • Difficulty concentrating


Along with treating depression, SSRIs (like Celexa and Prozac) are commonly used to provide quick relief of anxiety symptoms. They can treat all types of anxiety, including generalized anxiety, social anxiety disorder and panic disorders.

Celexa vs Prozac Dosage Amounts

Because citalopram (Celexa) and fluoxetine (Prozac) are both SSRIs, some people mistakenly believe they’re interchangeable. However, each drug has its own special dosage requirements. The chart below outlines the differences between Celexa and Prozac in terms of recommended starting dosages, absorption rates and available dosages and forms.

Recommended starting dose Length of time for drug to absorb Dosage forms Available dosages (for regular tablet)
Celexa 20 mg/day (up to 40 mg) 1 – 4 hours Tablet, oral solution 10 mg, 20 mg, 40 mg
Prozac 20 mg/day (up to 40 mg) 4 – 8 hours Tablet, delayed-release tablet, oral solution 10 mg, 20 mg, 60 mg
While they have similar recommended starting dosages, Prozac is available in higher dosages than Celexa. It also takes longer to absorb in the body.

Celexa vs Prozac Side Effects

Like any medication, citalopram and fluoxetine come with the risk of side effects. Since they both affect serotonin, many of these effects overlap. Here are some of the most common ones:

  • Headaches and nausea
  • Drowsiness and insomnia
  • Loss of appetite
  • Stomach problems (such as diarrhea and constipation)
  • Sexual side effects (such as sexual dysfunction)


Citalopram and fluoxetine also have their own unique side effects. For example, Celexa may cause excessive sweating (which doesn’t occur among Prozac users). Similarly, Prozac can trigger yawning.

As your body gets used to the medication, side effects should diminish — however, in some cases, they may persist or even worsen. Generally, if you metabolize drugs slowly, you’re at a higher risk of developing adverse effects. In the past, there was no way to accurately determine how someone would respond to a drug — that’s changed now thanks to pharmacogenetic testing.

ClarityX: Make Better Health Decisions With DNA Testing

If you want to know how you’ll react to a drug before you take it, then pharmacogenetic testing can help. Also known as genetic or DNA testing, it involves examining your genes to determine how you’ll respond to certain medications. This test focuses specifically on the cytochrome P450 enzyme, which is responsible for metabolizing over 70% of clinically used drugs.

At ClarityX, we offer comprehensive DNA tests that can tell you whether a drug will be ineffective, cause adverse effects or interact negatively with another medication you’re taking. We offer two types of tests:

  • Mindwell Test: Focuses on mental wellness treatments (such as antidepressants and SSRIs)
  • Max Rx Test: Includes everything in the Mindwell Test and 16 additional therapeutic fields


Both tests can be taken in the comfort of your own home. After you request your test and complete the check-out process. Then, you’ll receive a simple, at-home test. Once you perform a cheek swab and return the sample in the pre-paid envelope, you’ll get a thorough, personalized report in your patient portal!

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