If you have certain mental health conditions, your medical professional may recommend that you take a prescription drug called Prozac.

Prozac is used to treat the following conditions:

We’ll explain more about these conditions and how Prozac helps treat them in the “What do you take Prozac for?” section below.

* Prozac is prescribed in combination with olanzapine (Zyprexa) for this condition.

Prozac details

Prozac is a type of antidepressant drug called a selective serotonin reuptake inhibitor (SSRI). It contains the active drug fluoxetine.

Prozac comes as capsules that you swallow.

Prozac generic

Prozac is a brand-name medication. It’s also available as a generic drug called fluoxetine.

Most medications, including Prozac, may cause side effects that can be serious or mild. To give you an idea of what might occur with Prozac, we’ve listed some of the medication’s more common side effects below. Not all of the potential side effects are included here.

Your medical professional or pharmacist can provide more information on possible side effects of Prozac. They’ll also be able to recommend tips on how to help prevent and ease side effects.

Note: Certain factors may affect a medication’s side effects. These factors can include other health conditions you may have, other drugs you may be taking, and your age.

Mild side effects

Some of the mild side effects that Prozac may cause are listed below. For information about other mild side effects of the drug, we suggest that you talk with your medical professional or pharmacist. And it may also be helpful to refer to the medication guide.

Mild side effects of Prozac that have been reported in studies include the following:

Mild side effects of Prozac tend to ease or go away within a few days or weeks. But if you find that the side effects bother you, we encourage you to talk with your medical professional or pharmacist.

* For details on this side effect, you can see “Side effects: A closer look” below.
† You can see “Side effects specific to women and men” just below for details about possible sexual side effects of Prozac.

Serious side effects

Prozac may cause serious side effects, but this isn’t common. If you do develop serious side effects while taking Prozac, call your medical professional immediately. If you feel as if you’re having a medical emergency, call 911 or your local emergency number right away.

Serious side effects of Prozac that have been reported in studies include the following:

* For details on this side effect, you can see “Side effects: A closer look” below.

Side effects specific to women and men

The side effects of Prozac are generally expected to be the same for females* and males* who take the drug. (For more information, see the “Mild side effects” and “Serious side effects” lists above.)

However, females and males may experience different types of sexual side effects with Prozac.

For example, females taking Prozac have reported problems with reaching orgasm. Males taking Prozac have reported:

Other side effects of Prozac that are specific to females are related to using Prozac during pregnancy or while breastfeeding. For details, you can see the “What should you know before taking Prozac?” section below.

If you have questions about your risk for certain side effects from Prozac, a medical professional will be able to offer advice.

* Throughout this article, we refer to someone’s sex assigned at birth by using the terms “male” and “female.” To learn about the difference between sex and gender, you can refer to this article.

Prozac side effects in children and teens

Prozac is used to treat the following conditions in children and teenagers, in certain situations:

Most side effects of Prozac in children and teenagers are expected to be the same as the side effects seen in adults. (For more information, you can see the “Mild side effects” and “Serious side effects” lists above.)

However, Prozac has a boxed warning for suicidal thoughts and behaviors, especially in children, teenagers, and adults age 24 and younger. A boxed warning is a serious warning from the Food and Drug Administration (FDA). For details, you can see the “Side effects: A closer look” section just below.

Also, certain side effects of Prozac may be more common in children and teenagers than in adults. These include:

Side effects: A closer look

This section provides a close-up look at key side effects of Prozac.

Weight loss

Weight loss may occur with Prozac use. This side effect was common in studies of the drug.

Prozac can cause decreased appetite, which may lead to weight loss.

Changes in weight are a common symptom of depression and bulimia (a type of eating disorder). And Prozac is used to treat these conditions.

So if you have weight loss with Prozac, we recommend telling your medical professional right away. They’ll help determine if your weight loss is caused by the condition you’re using Prozac to treat, or if Prozac itself may be causing the weight loss.

Tips for managing

If you’re concerned about weight loss with Prozac, a medical professional may be able to answer any questions you have. They may monitor your weight while you’re taking the drug. They can also suggest ways for you to maintain a weight that’s healthy for you.

Tiredness

Taking Prozac can cause tiredness. This was a common side effect in studies of the drug.

However, Prozac can affect people differently. Both tiredness and insomnia (trouble sleeping) are possible side effects of the drug. So it’s possible that Prozac could either make you sleepy or keep you awake.

Tips for managing

Tiredness with Prozac can lead to problems with thinking, coordination, or judgment. For this reason, it’s recommended that you avoid driving until you know how Prozac affects you. You’ll likely know how Prozac will affect you after taking several doses of the drug.

If you’re concerned about tiredness while you’re taking Prozac, we encourage you to talk with your medical professional.

For some conditions Prozac is used to treat, it’s recommended to take the drug in the morning. But if taking Prozac makes you tired, it may be best to take your dose at bedtime. Your medical professional can recommend when it’s best for you to take Prozac.

Allergic reaction

Many drugs, including Prozac, can cause an allergic reaction.

Symptoms that can occur with a mild allergic reaction may include:

  • itchiness
  • skin rash
  • flushing (temporary warmth, redness, or deepening of skin color)

A more severe allergic reaction may also occur, but this is rare. Symptoms of a severe allergic reaction may include swelling of your mouth, tongue, or throat, which may cause trouble breathing. You may also experience swelling under your skin, often in your lips, eyelids, hands, or feet.

Tips for managing

If you have symptoms of an allergic reaction to Prozac, call your medical professional immediately. If you feel as if you’re having a medical emergency, call 911 or your local emergency number right away.

Boxed warning

Prozac has a boxed warning from the Food and Drug Administration (FDA). The boxed warning appears on the drug’s label and alerts you to possible serious risks.

Suicidal thoughts and behaviors. Antidepressants, such as Prozac, can raise the risk of suicidal thoughts and behaviors. This risk may be highest for children, teenagers, and adults who are age 24 or younger.*

And regardless of your age, your risk may also be higher if your Prozac dosage has been changed recently, or if you started taking the drug recently (within a few months ago).

While you’re taking Prozac, watch for the following symptoms:

* Prozac is only approved to treat certain types of depression in children and teenagers, in some situations. For details, you can see the “What do you take Prozac for?” section below.

Tips for managing

If you have unusual changes in your thoughts, moods, behaviors, or feelings while taking Prozac, tell your medical professional right away. They may change your treatment plan or prescribe a drug for you other than Prozac. And if you have thoughts about harming yourself, it’s important to get help right away.

Suicide prevention

If you or someone you know is considering suicide, you’re not alone. Help is available right now:

Not in the U.S.? Find a helpline in your country with Befrienders Worldwide.

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Your medical professional can advise you on how much Prozac to take and how often. Commonly used dosages are mentioned below, but always take the dosage your medical professional recommends.

Your medical professional may prescribe a different dosage depending on certain factors, such as:

  • your age
  • other health conditions you have
  • other medications you take

Form and strengths (10 mg, 20 mg, 40 mg)

Prozac comes as capsules that you swallow.

The drug is available in the following strengths: 10 milligrams (mg), 20 mg, and 40 mg.

Recommended dosages

Below are the recommended dosages of Prozac for each condition the drug is used to treat. Your medical professional will monitor the effects of Prozac week by week to determine if your dosage needs to be adjusted.

  • Dosage for panic disorder with or without agoraphobia: The typical starting dosage of Prozac for panic disorder (a type of anxiety) is 10 mg each day. The usual maximum dose of Prozac for panic disorder is 60 mg per day.
  • Dosage for OCD: The typical starting dosage of Prozac for obsessive-compulsive disorder (OCD) is 20 mg each morning. The usual maximum dose of Prozac for OCD is 60 mg per day.
  • Dosage for depression: The usual starting dosage of Prozac for major depressive disorder (MDD), which is also called depression, is 20 mg each morning. The maximum dose of Prozac for depression is 80 mg per day.
  • Dosage for bulimia: The usual starting dosage of Prozac for bulimia is 60 mg each morning, which is also the maximum dose of Prozac for this use.
  • Dosage for episodes of depression caused by bipolar I disorder: For episodes of depression with bipolar I disorder, Prozac is used in combination with olanzapine (Zyprexa).* The typical starting dosage of Prozac for this purpose is 20 mg each evening. The usual maximum dose of Prozac for depression episodes caused by bipolar I disorder is 50 mg per day.
  • Dosage for treatment-resistant depression: For treatment-resistant depression, Prozac is used in combination with olanzapine (Zyprexa).* The usual starting dosage of Prozac for this purpose is 20 mg each evening. The typical maximum dose of Prozac for treatment-resistant depression is 50 mg per day.

* Fluoxetine (the active drug in Prozac) is available in combination with olanzapine as the brand-name drug Symbyax. Your medical professional or pharmacist can advise whether Symbyax is right for you.

Here are the answers to some commonly asked questions about Prozac.

Is Prozac used to treat anxiety?

One of the conditions Prozac is approved to treat is panic disorder, which is a specific type of anxiety. But Prozac may also be prescribed off-label to treat other types of anxiety. (Off-label means using a drug for a condition it hasn’t been approved to treat.)

Specifically, Prozac is sometimes used off-label to treat:

Your medical professional or pharmacist can provide more information about using Prozac to treat these conditions or other types of anxiety.

Does Prozac cause weight gain?

No, weight gain wasn’t reported as a side effect in studies of Prozac.

Prozac is used to treat depression and bulimia (a type of eating disorder). And weight changes are known to happen with these conditions.

If you have weight gain while taking Prozac, your medical professional can help determine if the weight gain is caused by Prozac or by the condition you’re using Prozac to treat. They can also help you with managing a weight that’s healthy for you.

Does the half-life of Prozac affect how long it stays in your system?

Yes. The amount of time you’ve been taking Prozac can also affect how long the drug stays in your system.

Half-life refers to the time it takes for your body to get rid of half of a drug’s dose. The half-life of Prozac is shorter for people who’ve just started taking the drug compared with people who’ve taken several doses.

When you start taking Prozac, the drug’s half-life is about 1 to 3 days. After you’ve taken several doses, Prozac’s half-life extends to 4 to 6 days.

It usually takes about five half-lives for a drug to leave your system entirely. This means Prozac will stay in your system for about 5 to 15 days after your first few doses. But after several doses, the drug will stay in your system for about 20 to 30 days.

What does Prozac feel like when it starts working?

Prozac can help improve your emotions and mood. But you may not feel the effects of it right away. It can take several weeks for you to notice the drug’s effects. Over time, you may notice that you feel more relaxed, less worried, and less tense than before you started taking Prozac.

Your medical professional or pharmacist can answer any questions you may have about what to expect with Prozac treatment.

Is Prozac a controlled substance?

No, Prozac is not a controlled substance.

Controlled substances are medications that have high potential for misuse or for being addictive. (With misuse, a drug is taken differently than how it’s prescribed. And with addiction, a drug continues to be taken even if it’s causing harm.)

These effects aren’t known to happen with Prozac. But your medical professional will help make sure you’re taking the drug safely and as prescribed.

Before taking Prozac, it’s recommended that you talk with your medical professional about:

  • your overall health
  • medical conditions you have
  • any other medications you take

We discuss these considerations in more detail below.

Interactions

Taking certain drugs, foods, vaccines, and other substances with a medication may affect how that medication works. These effects are known as interactions.

Before you take Prozac, it’s important to talk with your medical professional about any other drugs you take. This includes prescription and over-the-counter medication. It’s also essential to mention any herbs, supplements, and vitamins you may use.

Your medical professional or pharmacist can tell you about possible interactions these substances may have with Prozac.

Interactions with drugs or supplements

Prozac can interact with several types of drugs. These include:

We haven’t listed all types of drugs that may interact with Prozac. Your medical professional or pharmacist can provide more details as well as information on other possible interactions.

* Because of this interaction, you should not take Prozac if you’re taking these medications.

FDA boxed warning

Prozac has a boxed warning from the Food and Drug Administration (FDA) about suicidal thoughts and behaviors. The boxed warning appears on the drug’s label and alerts you to possible serious risks.

This risk is highest for children, teenagers, and young adults who take an antidepressant, such as Prozac.

For details, see “Side effects: A closer look” in the “Does Prozac have side effects?” section above.

Other warnings

If you have certain medical conditions or other factors that affect your health, Prozac may not be the right choice for you. Before you take Prozac, it’s important to discuss your health history with your medical professional. The list below includes some factors to consider.

  • Diabetes. Prozac can make it hard to manage blood sugar levels. If you have diabetes, your medical professional may watch your blood sugar levels more closely than usual if you take Prozac.
  • Heart problems. If you have heart problems, Prozac may cause an abnormal heart rhythm. Your risk for this side effect may be higher, and your medical professional may monitor your heart closely during treatment.
  • Liver problems. If you have liver problems, such as cirrhosis, your body may have trouble removing Prozac from your system. This could cause the drug to build up in your body, which increases your risk for side effects from Prozac. Let your medical professional know about any liver problems you have.
  • Allergic reaction. If you’ve had an allergic reaction to Prozac or any of its ingredients, you should not take Prozac. Your medical professional can recommend other treatments that might be better choices for you.

Prozac and alcohol

It’s recommended to avoid drinking alcohol during treatment with Prozac. Drinking alcohol while taking the drug can worsen certain side effects of the drug, such as tiredness.

If you drink alcohol, talk with your medical professional about whether it’s safe to drink while you’re taking Prozac.

Prozac use while pregnant or breastfeeding

It may not be safe to take Prozac during pregnancy. Taking the drug during pregnancy can increase the risk of heart problems in the fetus.

If you take Prozac during pregnancy, consider enrolling in a pregnancy registry. Pregnancy registries collect details about the effects of a drug used during pregnancy. This information can help researchers understand the risks of using the drug during pregnancy.

To enroll in the National Pregnancy Registry for Antidepressants and report side effects of Prozac if used during pregnancy, visit the registry’s site. Or call 844-405-6185. It’s important to talk with your medical professional about the risks and benefits of taking Prozac while you’re pregnant.

Additionally, Prozac can pass into breast milk. If you’re breastfeeding while taking Prozac, it’s recommended that you watch your child for these side effects:

Your medical professional can advise you about taking Prozac while you’re breastfeeding.

While researching Prozac, you may wonder how the drug compares with alternatives such as sertraline (Zoloft). You may wonder about other drugs as well, such as paroxetine (Paxil) and bupropion (Wellbutrin).

Prozac, Zoloft, and Paxil belong to a group of antidepressant drugs called selective serotonin reuptake inhibitors (SSRIs). Wellbutrin belongs to a group of drugs called norepinephrine and dopamine reuptake inhibitors (NDRIs). All of these drugs are used to treat forms of depression and anxiety.

To learn about the similarities and differences between Prozac and Zoloft, you can refer to this comparison article. You can also ask your medical professional or pharmacist whether any of these drugs are right for you.

Both Prozac and escitalopram (Lexapro) belong to a group of antidepressant drugs called selective serotonin reuptake inhibitors (SSRIs). And both drugs can be used to treat forms of anxiety and depression.

To learn how Prozac and Lexapro are alike and different, you can refer to this comparison article. Your medical professional or pharmacist can answer any additional questions you may have.

Suddenly stopping Prozac can cause withdrawal symptoms. This can happen within days of stopping Prozac treatment. And they may last for several weeks after your last dose.

However, Prozac is less likely to cause withdrawal symptoms than other antidepressant drugs. This is because Prozac can stay in your body for many days after you take it.*

Possible symptoms of withdrawal from Prozac can include:

Don’t stop taking Prozac unless your medical professional says it’s safe to do so. When it’s time for you to stop taking the drug, your medical professional will explain how to wean off Prozac. This will help lower your risk for withdrawal symptoms.*

Your medical professional can answer any questions you may have about the withdrawal timeline for Prozac.

* For details, you can see “Does the half-life of Prozac affect how long it stays in your system?” in the “What are some common questions about Prozac?” section above.

If you have certain mental health conditions, your medical professional may recommend that you take Prozac. Below, we describe the conditions that Prozac may be prescribed to treat.

Prozac for panic disorder

Prozac can be used in adults to treat panic disorder with or without agoraphobia. Panic disorder is a type of anxiety. You may have sudden, strong symptoms of anxiety that seem to happen without a known cause. Agoraphobia is an intense fear of being in public.

Symptoms of panic disorder can include:

Prozac for OCD

Prozac can be used to treat obsessive-compulsive disorder (OCD) in adults and in children ages 7 years and older. With OCD, you experience obsessions (repeated, unwanted thoughts) in combination with compulsions (overwhelming urges to do certain actions).

These obsessions can lead to stress and anxiety, and compulsions can offer some relief for this stress and anxiety.

Prozac for depression

Prozac can be used to treat major depressive disorder in adults and in children ages 8 years and older. With this condition, you have depression symptoms almost every day for at least 2 weeks.

Symptoms of depression can include:

Prozac for bulimia

Prozac is used in adults to treat bulimia nervosa. With this eating disorder, you may be focused on food, body image, and weight. And this can lead you to binge and purge.

Bingeing describes eating a large amount of food in a very short period of time. And purging refers to getting rid of the food in some way, such as forcing yourself to vomit.

Prozac for episodes of depression caused by bipolar I disorder

Bipolar disorder is a condition that causes sudden, extreme changes in mood. It generally involves episodes of depression as well as episodes of mania (extremely high energy and excitement).

Bipolar I disorder means someone has had at least one episode of mania. Prozac is used to treat the episodes of depression that also happen with this condition.

Prozac can be used to treat episodes of depression in adults and in children ages 10 years and older. For this purpose, Prozac is taken in combination with olanzapine (Zyprexa).*

* Fluoxetine (the active drug in Prozac) is available in combination with olanzapine as the brand-name drug Symbyax. Your medical professional or pharmacist can advise whether Symbyax is right for you.

Prozac for treatment-resistant depression

Prozac can be used for treatment-resistant depression in adults. With this condition, you have depression symptoms that haven’t improved after trying at least two other antidepressant drugs.

For this purpose, Prozac is used in combination with olanzapine (Zyprexa).

How Prozac works

Prozac belongs to a group of antidepressant drugs called selective serotonin reuptake inhibitors (SSRIs).

The drug works by increasing the level of a chemical in your brain called serotonin. Higher levels of serotonin can help improve your emotions and mood.

Prozac for children

Prozac is used to treat the following conditions in some children:

How Prozac works

Prozac belongs to a group of antidepressant drugs called selective serotonin reuptake inhibitors (SSRIs).

The drug works by increasing the level of a chemical in your brain called serotonin. Higher levels of serotonin can help improve your emotions and mood.

Prozac for children

Prozac is used to treat the following conditions in some children:

See the rest of this section above for details about these conditions.

It’s important that you do not take more Prozac than your medical professional recommends. Taking more than the recommended dosage can lead to severe side effects.

Symptoms of overdose

Symptoms caused by an overdose can include:

What to do in case you take too much Prozac

If you believe you’ve taken too much Prozac, call your medical professional right away. You can also call 800-222-1222 to reach the American Association of Poison Control Centers, or use its online resource. But if your symptoms are severe, immediately call 911 (or your local emergency number) or go to the closest emergency room.

Your medical professional can help explain how to take Prozac. It’s important to follow the instructions they provide.

Below are a few suggestions for how to take Prozac.

Tips for taking Prozac

Prozac comes as capsules that you swallow whole. You’ll likely take the capsules once a day.

Depending on the condition you’re taking the drug to treat, you may take Prozac in the morning or in the evening. But regardless of when you take it, try to take your doses around the same time each day. This helps keep a steady level of the drug in your system, which can help prevent withdrawal symptoms.

Until you know how Prozac affects you, it’s recommended that you avoid driving or doing tasks that require you to think clearly. The drug can cause tiredness, which can be dangerous while you’re driving. After taking several doses, you’ll likely know whether Prozac will cause these effects for you.

Your medical professional can answer any questions you may have about how to take Prozac.

Taking Prozac with other drugs

Your medical professional may prescribe Prozac along with other drugs to treat your condition.

But before starting Prozac, it’s important to tell your medical professional about any other drugs you take. This is because certain drugs may affect how Prozac works or they may raise your risk for side effects from Prozac.

For example, taking Prozac with amphetamine (Adderall XR) can raise your risk for serotonin syndrome. This condition is caused by a high level of a chemical in your brain called serotonin. This condition can be dangerous.

For more information about possible interactions with Prozac, you can see the “What should you know before taking Prozac?” section above.

How long it takes for Prozac to work

After you start taking Prozac, it may take up to several weeks for your symptoms to improve. We encourage you to talk with your medical professional about when you can expect to notice that Prozac is working for you.

Frequently asked questions about taking Prozac

We’ve provided the answers below to some frequently asked questions about using Prozac:

  • What’s the best time to take Prozac? Depending on the condition you’re using the drug to treat, you may take Prozac in the morning or in the evening. But regardless of when you take it, try to take your dose at about the same time each day. This helps keep a steady level of the drug in your system, which can help prevent withdrawal symptoms.
  • What should I do if I miss a dose of Prozac? If you miss a dose of Prozac, take your missed dose as soon as you remember. But if it’s almost time for your next dose, just skip your missed dose. Then take your next dose at the regular time. Do not take two doses of Prozac to make up for a missed dose. Doing so can increase your risk for side effects from the drug. If you aren’t sure whether to take a dose or skip it, ask your medical professional or pharmacist.
  • Is Prozac meant for long-term use? Your medical professional may prescribe Prozac for long-term use. If the drug is working for you and isn’t causing bothersome side effects, you’ll likely take it long term.
  • Can you chew, split, or crush Prozac? It may not be safe to chew, split, or crush Prozac. Your medical professional or pharmacist can offer advice if you’re unable to swallow the capsules whole.
  • Should you take Prozac with food? You can take Prozac with food or without it.
What should you ask your medical professional?

It’s common to have questions about your treatment plan for Prozac. Your medical professional will work with you to help address any concerns you have.

To help guide your discussion, here are some suggestions:

  • Try writing down questions you have before your visit. For example, “How will taking Prozac affect my mood, body, and lifestyle?”
  • Think about asking a loved one or friend to come with you to your appointment. Having in-person support may help you feel more at ease.
  • If your medical professional says something that’s unclear, you can always ask them to explain it.

Working with your healthcare team may help you stay on track with your treatment. The team wants you to get the best care possible.

Prozac is a prescription drug. The costs of prescription medications may depend on several factors, such as your insurance coverage and the pharmacy you use.

Prozac is available as a generic drug called fluoxetine. A generic is a copy of the active drug in a brand-name medication. The generic may cost less than the brand-name form. Your medical professional can help determine if the generic form of Prozac may be an option for your treatment.

If you’re wondering how to pay for Prozac, discuss this with your medical professional or pharmacist. You may also want to visit the website of the Prozac manufacturer to see if support options are available.

Studies of Prozac haven’t shown a high risk of misuse. (Misuse means taking a drug differently than how it’s prescribed.)

But it is possible that Prozac may be misused. To lower your risk of misuse, it’s important to take Prozac exactly as your medical professional has prescribed.

If you still have questions about Prozac after reading this article, we recommend talking with your medical professional. Together you can decide if Prozac might be a good choice for you.

You can also discuss other treatments, forms of support, and resources that may benefit you. We’ve listed some helpful suggestions below.

Additional treatment options

While you take Prozac, additional treatments or remedies may help you manage your condition better. These can include:

Finding support

Whether you’re looking for a therapist, support group, or information on how to afford therapy, these resources may help:

Other resources

To receive weekly information on mental health, you may want to sign up for the Psych Central newsletter. You’ll find stories directly from other people on their mental health journey as well as the latest information on treatments.

Q:

Will the symptoms of my condition come back after I stop taking Prozac?

Anonymous patient

A:

It’s possible that symptoms of your condition may come back after you stop taking Prozac. After you stop your treatment, a medical professional will continue to monitor you for symptoms.

If you have any changes in your mood or behavior after stopping Prozac, including suicidal thoughts, it’s important to call your medical professional immediately.

It’s also important to talk with a medical professional before you stop taking Prozac. The two of you can decide whether stopping it is right for you. And your medical professional can recommend how to stop taking the medication safely.

Neal Patel, PharmDAnswers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.
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Disclaimer: Psych Central has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.