Lexapro vs Prozac: Differences, Similarities, and Which is Better

Escitalopram (Lexapro) and Fluoxetine (Prozac) are two of the most well known antidepressants on the market, with millions of prescriptions for each drug being written in the United States each year. 

Both medications belong to a class of medications called selective serotonin reuptake inhibitors (SSRIs) and work in a similar way to treat symptoms of depression.

When considering Lexapro vs. Prozac, there are significant differences and similarities to consider.

Conditions Treated

Lexapro and Prozac are both brand-name Food and Drug Administration (FDA)-approved antidepressant medications for the treatment of major depressive disorder, which is sometimes referred to as clinical depression.

 Lexapro is approved for the treatment of major depressive disorder in patients who are 12 years of age or older, while Prozac is used for the treatment of the condition in children ages 8 and older and adults. 

Symptoms of major depressive disorder are severe, last for at least two weeks or more, and include:

  • Feeling sad, empty, or tearful
  • Feelings of worthlessness, guilt, hopelessness, or helplessness
  • Lost of interest in activities you used to enjoy
  • Nervous energy
  • Difficulty concentrating
  • Feelings of moving or thinking in slow motion
  • Sleeping and eating more or less than usual
  • Low energy
  • Suicidal thoughts or behaviors

In addition to treating major depressive disorder, Lexapro is also used for the treatment of generalized anxiety disorder in adults. 

In addition to treating major depressive disorder, Prozac is also used to treat obsessive-compulsive disorder (OCD), panic disorder and panic attacks, bulimia nervosa, bipolar disorder, and premenstrual dysphoric disorder.


Lexapro and Prozac are two of the most popular antidepressants on the market, and several studies have been conducted that compare their effectiveness. 

A literature review that compared the results of the studies showed that Lexapro and Prozac can be considered equally effective when treating major depressive disorder, which is the only condition that both medications are approved to treat.

It should be noted that while the drugs were found to be equally effective, not everyone will respond to each medication the same way. Some people will naturally experience better results or have a lower incidence of side effects when taking one medication compared to the other.

No matter whether your doctor prescribes Lexapro or Prozac for the treatment of your depression, you should expect to give the medication at least four weeks to start working.

Some people may notice a reduction in their physical symptoms in as little as two weeks, but mood symptoms typically take four to six weeks to resolve. 

Side Effects

Prozac is typically associated with more significant side effects than Lexapro. While both drugs have a long list of side effects, Lexapro users typically report the effects as being more mild.

Lexapro has a shorter half life than Prozac, which means that the body metabolizes the medication more quickly. As a result, patients generally experience side effects for a shorter amount of time and with less intensity. 


In general, the side effects associated with Lexapro are considered less severe than the side effects associated with Prozac.

However, Lexapro is still associated with many side effects.  The side effects of Lexapro are slightly different for children and adults. 

Common side effects of Lexapro use in adults include:

  • Gastrointestinal effects including nausea
  • Shaking
  • Weakness
  • Infection
  • Sleepiness
  • Dizziness
  • Trouble sleeping
  • Sweating
  • Weight gain
  • Anxiety
  • Unusual changes in sex drive and other sexual issues like erectile dysfunction and premature ejaculation 
  • Dry mouth
  • Loss of appetite
  • Constipation
  • Yawning

Children and adolescents may experience the same possible side effects listed above for adults, but may also experience other side effects, including:

  • Nosebleeds
  • Heavy menstrual periods
  • Slowed growth and weight change or weight loss
  • Increased thirst
  • Abnormal increase in muscle movement or agitation
  • Trouble urinating

Lexapro can also cause rare but serious side effects in addition to the more mild side effects listed above. Rare but serious side effects associated with Lexapro include:

  • Severe allergic reaction, as indicated by:
    • Severe rash, hives, or blisters that may be accompanied by fever or joint pain
    • Swelling of the face, tongue, eyes, or mouth
    • Difficulty breathing
  • Seizures or convulsions
  • High or Low Blood Pressure
  • Low sodium levels, as indicated by:
    • Confusion
    • Thinking or memory problems
    • Irregular heartbeat
    • Weakness
    • Seizures
    • Headache
    • Trouble concentrating
    • Unsteadiness that can lead to falls
  • Serotonin syndrome, as indicated by:
    • Fever
    • Seizures
    • Shivering
    • Severe muscular tightness
    • Diarrhea
    • Confusion
    • Death
  • Manic episodes, as indicated by:
    • Severe sleeping trouble
    • Unusually grand ideas
    • Reckless behavior
    • Racing thoughts
    • Greatly increased energy
    • Talking quickly or more than normal
    • Excessive happiness or irritability
  • Vision problems, as evidenced by:
    • Swelling or redness in or around your eye
    • Eye pain
    • Changes in your vision

If you experience any of these side effects or withdrawal symptoms, seek medical attention immediately.


Side effects associated with Prozac are more likely to be moderate or severe than the side effects associated with Lexapro.

The side effects associated with Prozac generally fall into two categories: common and rare but serious. 

Common side effects associated with Prozac include:

  • Weight loss
  • Diarrhea
  • Dry Mouth or sore throat 
  • Drowsiness and tiredness
  • Increased sweating
  • Headache
  • Fatigue
  • Feeling nervous
  • Increased bruising or minor skin rashes
  • Nausea
  • Difficulty sleeping (insomnia)
  • Decreased libido or sex drive
  • Restlessness
  • Sexual dysfunction, such as difficulty with orgasm or ejaculatory delay

Rare but serious side effects of Prozac include:

  • Low blood sodium levels, as indicated by:
    • Headache
    • Difficulty concentrating
    • Difficulty remembering
    • Weakness
  • Teeth grinding
  • Angle-closure glaucoma, as evidenced by:
    • Changes in vision
    • Eye pain
    • Swelling or redness in or around the eye
  • Serotonin syndrome, as evidenced by:
    • Shivering
    • Confusion
    • Severe muscular tightness
    • Fever
    • Seizures
    • Diarrhea
    • Death
  • QT prolongation and ventricular arrhythmia including changes in the electrical activity of your heart


Lexapro and Prozac are both used for the treatment of major depressive disorder but otherwise treat different mental health conditions.

The medications are considered equally effective for the treatment of depression, but Lexapro is associated with a lower incidence and severity of adverse effects. 

Your medical provider will be able to tell you whether Lexapro or Prozac could have drug interactions with other medications you’re taking such as monoamine oxidase inhibitors (MAOIs), serotonin and norepinephrine reuptake inhibitors SNRIs, triptans, nonsteroidal anti-inflammatory drugs (NSAIDs), or tricyclic antidepressants. 

These can include lithium, sertraline (Zoloft), venlafaxine (Effexor), paroxetine (Paxil), or citalopram (Celexa).

Seek medical advice from your prescribing healthcare provider to see if Lexapro, Prozac, or their generic name counterparts are the right prescription drugs to treat your body’s major depression. 

References, Studies and Sources:




author avatar
Angel Rivera
I am a Bilingual (Spanish) Psychiatrist with a mixture of strong clinical skills including Emergency Psychiatry, Consultation Liaison, Forensic Psychiatry, Telepsychiatry and Geriatric Psychiatry training in treatment of the elderly. I have training in EMR records thus very comfortable in working with computers. I served the difficult to treat patients in challenging environments in outpatient and inpatient settings

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