Prozac for Anxiety Disorders

Side Effects, Interactions, and Risks

Possible Effects of Prozac

Verywell / Cindy Chung 

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Prozac (fluoxetine) is an antidepressant that was first introduced in the United States to treat depression in the 1980s. It is part of a class of medications known as selective serotonin reuptake inhibitors (SSRIs).

Prozac is mainly used to treat major depression, obsessive-compulsive disorder, and panic disorder (of which are approved uses by the Food and Drug Administration) but is also sometimes used off-label to treat other anxiety disorders.


As an SSRI, Prozac works by preventing the brain from reabsorbing naturally occurring serotonin. Serotonin is involved in mood regulation. In this way, Prozac helps the brain to maintain enough serotonin so that you have a feeling of well-being, resulting from improved communication between brain cells.

Research also highlights how medications such as Prozac may help in combination with psychotherapy. In a 2008 mice study published in Science, it was shown that Prozac helped the brain to enter a more immature and plastic state, possibly making it easier for therapy to have an effect.

Studies like this have provided insight into the fact that combining medication such as Prozac with talk therapy is effective for anxiety.

What It Feels Like to Take Prozac

If you experience a positive response to Prozac, you might notice a decrease in your anxiety symptoms and feel more like yourself again:

  • More relaxed
  • Less anxious
  • Improved sleep and appetite
  • Greater interest in life
  • Increased energy
  • Improved focus

Remember that it may take time for these improvements to become noticeable—even up to 12 weeks in some cases. You may also experience side effects at first, so it may be hard to notice the improvements until the side effects lessen.

Using Prozac for Anxiety

Prozac is often considered a first-line treatment for anxiety disorders. However, there are a number of steps involved in obtaining a prescription. Generally, a diagnosis of a mental health disorder must be given before you would be prescribed Prozac.

While a family doctor is capable of writing a prescription, the process is better handled by a mental health professional with experience in mental health disorders, such as a psychiatrist, who can also prescribe medication.

Dosage and Administration

Prozac is usually prescribed at a low dose to start, and then gradually increased to 20mg per day. The maximum dose is 80mg a day. It is taken as a liquid or capsule and should be used as prescribed. It can take several weeks for effects to show, so it is important not to stop taking Prozac abruptly if you think it is not working.

Only take the medication as prescribed by your doctor or psychiatrist. Stopping cold turkey could be dangerous and cause withdrawal symptoms.


There has been some controversy as to the safety of Prozac, due to the issuing of a safety warning by the Food and Drug Administration in 2007 about the risk for suicidal thoughts among certain groups.

Despite this warning, Prozac continues to be prescribed and can be used safely (or discontinued if adverse effects develop) when under the guidance of a physician. If you have concerns about the safety of taking Prozac, bring these up to your doctor.

Medication Interactions

Prozac should not be combined with monoamine oxidase inhibitors (MAOIs) or taken within 14 days of discontinuing an MAOI.

Allow at least five weeks after stopping Prozac before starting an MAOI. Use of pimozide and thioridazine also increases the risk involved in taking Prozac. The result of medication interactions can be serious and potentially fatal, so you should discuss all medications you are taking with your doctor or psychiatrist to determine whether potential interactions exist.

Side Effects 

Some side effects of Prozac are more likely than others. Some people notice that side effects lessen over time, or become less bothersome.

Common side effects include:

  • Sleep problems
  • Headaches
  • Fatigue
  • Dizziness
  • Nausea
  • Loss of appetite
  • Anxiety
  • Lightheadedness
  • Yawning
  • Sweating
  • Sexual problems
  • Dry mouth
  • Heartburn
  • Diarrhea
  • Blurred vision

Rare side effects include:

  • Vomiting
  • Seizures
  • Rash/hives
  • Fever
  • Swelling
  • Feeling confused
  • Extreme anxiety
  • Trouble breathing or swallowing
  • Bleeding or bruising
  • Suicidal thoughts or behavior

If you experience any of these severe side effects, be sure to notify your doctor or psychiatrist.

Who Should Not Take Prozac

Prozac can be passed to babies during pregnancy and through breast milk. Consult with your doctor if you are pregnant or nursing before taking Prozac, to determine whether the benefits outweigh the risks.

There are also some potential risks for individuals age 65 or older that should be discussed with your doctor. The safety and effectiveness of Prozac for use with children younger than 18 years of age has also not been established. 

Drug Interactions

Prozac should not be combined with alcohol, certain over-the-counter (e.g., aspirin, due to the risk of bleeding) and prescription medications, and nutritional supplements or herbs (e.g., St. John's Wort). Be sure to tell your doctor about everything that you are taking.

Prozac should not be taken at the same time as monoamine oxidase inhibitors (MAOIs) (pimozide and thioridazine), tricyclic antidepressants (TCAs), or drugs metabolized by CYP2D6. Care should also be taken if using drugs that affect the central nervous system (CNS), such as benzodiazepines.


Use of Prozac can carry risks, including the potential for clinical worsening and in rare cases, increased thoughts of suicide. Serotonin syndrome can also occur, particularly if used in conjunction with certain other medications. Close monitoring by your psychiatrist or doctor is important.

Prozac also comes with a black box warning that it may increase the risk of suicide in people younger than 25 years old. In these individuals, it may lead to suicidal thoughts, or worsening of these types of thoughts. If you belong to this group, your doctor should monitor you, particularly in the early stages, for these serious issues.

If you are having suicidal thoughts, contact the National Suicide Prevention Lifeline at 1-800-273-8255 for support and assistance from a trained counselor. If you or a loved one are in immediate danger, call 911. 

For more mental health resources, see our National Helpline Database.

Prozac may also activate mania in people who are prone.


If you stop taking Prozac all of a sudden, you may notice withdrawal symptoms, including:

  • Dizziness
  • Confusion
  • Nightmares
  • Insomnia
  • Irritability
  • Crying spells

For this reason, never stop a medication without consulting your doctor. Prozac should always be tapered off to avoid withdrawal effects.

Other Options

If Prozac is not well tolerated, other SSRIs that are sometimes prescribed for anxiety include: 

Effexor XR (venlafaxine) is another antidepressant called a serotonin-norepinephrine reuptake inhibitor (SNRI) that also may be effective in treating your anxiety.

Finally, benzodiazepines are another class of medication often used for anxiety, but they are generally a short-term solution because of their risk of dependence. Typical medications in this category include:

A Word From Verywell

If you've been prescribed Prozac for anxiety, you may feel worried about side effects and whether the medication will be helpful. Share your concerns with your doctor and stay in contact about how you are doing once you begin the medication. Communication is key to ensuring that this medication is used in an appropriate way for maximum effectiveness.

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5 Sources
Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  2. Maya Vetencourt JF, Sale A, Viegi A, et al. The antidepressant fluoxetine restores plasticity in the adult visual cortex. Science. 2008;320(5874):385-8. doi:10.1126/science.1150516

  3. National Alliance on Mental Illness. Fluoxetine (Prozac). Updated December 2020.

  4. Cleveland Clinic. Fluoxetine oral solution.

  5. FDA. Highlights of prescribing information.

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