Dosages for Prozac (fluoxetine) may vary based on your age and the condition it’s used to treat. The typical starting dosage ranges from 10 to 60 milligrams (mg) daily. Your doctor may adjust your dosage over the course of your treatment.
Prozac is prescribed on its own to treat:
- panic disorder with or without agoraphobia in adults
- bulimia nervosa (an eating disorder) in adults
- major depressive disorder (also known as depression) in adults and some children
- obsessive-compulsive disorder (OCD) in adults and some children
Prozac may also be prescribed in combination with olanzapine (Zyprexa) to help treat:
- treatment-resistant depression in adults
- depression related to bipolar I disorder in adults and some children
The active ingredient in Prozac is fluoxetine. Prozac belongs to a group of drugs called selective serotonin reuptake inhibitors (SSRIs).
This article describes the dosages of Prozac, its strengths, and how to take it. To learn more about Prozac, see this in-depth Prozac overview.
Boxed warning: Risk of suicidal thoughts and behaviors
Prozac has a boxed warning about the risk of suicidal thoughts and behaviors. A boxed warning is the most serious warning from the Food and Drug Administration (FDA). It alerts doctors and patients about drug effects that may be dangerous.
The risk of suicidal thoughts and behaviors affects children and young adults (ages 24 years and younger) who take antidepressants, such as Prozac. This risk is higher during the first few months of treatment and after dosage changes. Note that Prozac is not approved for use in children younger than age 7 years.
During Prozac treatment, the doctor will monitor you or your child closely for suicidal thoughts and behaviors.
If a family member or someone you live with takes Prozac, watch for symptoms of worsening depression. Symptoms can include feeling sad or hopeless, sleeping more or less than usual, and changes in mood. Also watch for anxiety or panic attacks. It’s especially important to watch for these symptoms during the first few months of treatment and following dosage changes.
If you or your child has suicidal thoughts during Prozac treatment, tell your or your child’s doctor right away. You can also refer to this article for ways to seek support.
For more details about this boxed warning, talk with your doctor. You can also read more about the boxed warning and other possible effects in this Prozac side effects article.
Your doctor will likely start you on a low dosage and adjust it over time to reach the right amount for you. They’ll ultimately prescribe the smallest dosage that provides the desired effect.
The following chart highlights the basics of Prozac’s dosage. All doses are listed in mg.
Always take the dosage your doctor prescribes for you. They’ll determine the best dosage to fit your needs. In some cases, doctors may adjust your dosage from those shown here.
| Condition | Starting dosage | Maximum dosage |
|---|---|---|
| panic disorder | 10 mg per day | 60 mg per day |
| OCD | 20 mg per day | 80 mg per day |
| depression | 20 mg per day | 80 mg per day |
| treatment-resistant depression* | 20 mg per day | 50 mg per day |
| depression related to bipolar I disorder* | 20 mg per day | 50 mg per day |
| bulimia nervosa (an eating disorder)† | 60 mg per day | 60 mg per day |
* For this condition, Prozac is used together with olanzapine (Zyprexa).
† For this condition, doctors may prescribe a lower dose to start. Then they’ll increase it over several days to the recommended dose of 60 mg.
Prozac forms
Prozac comes as a capsule that you swallow.
Prozac strengths
Prozac capsules come in the following strengths:
- 10 mg
- 20 mg
- 40 mg
Prozac is approved to treat the following conditions:
- panic disorder
- bulimia nervosa
- depression
- OCD
- treatment-resistant depression
- depression related to bipolar I disorder
The prescribed Prozac dosage may vary depending on the condition it’s used to treat. Always follow your doctor’s instructions. Notify them if you experience any side effects that may prevent you from taking your medication.
Dosage for panic disorder
For panic disorder (a kind of anxiety disorder), your doctor may initially prescribe a low dose of Prozac. The starting dosage is 10 mg per day.
After 1 week, your doctor may increase your dosage to 20 mg per day. This is the recommended dosage for panic disorder. They may increase it further to reach the dose that’s right for you.
The usual daily dose ranges from 10 to 60 mg. The maximum recommended dosage for panic disorder is 60 mg.
Dosage for bulimia nervosa
For bulimia nervosa, the usual dosage of Prozac is 60 mg per day. Doctors sometimes prescribe a lower dose to start. Then, they’ll increase it over several days until they reach the recommended dose.
For this use, 60 mg per day is the recommended dosage and the maximum dosage of Prozac.
Dosage for depression
For depression in adults, the typical dosage of Prozac is 20 mg per day. You’ll likely take this dosage for the first several weeks or longer. Then, your doctor may adjust your dosage over time to reach the dose that’s right for you.
The usual daily dose ranges from 20 to 80 mg. The maximum recommended dosage is 80 mg per day.
Dosage for OCD
For OCD in adults, the recommended starting dosage is 20 mg per day. Your doctor may gradually increase your dosage to reach the dose that’s right for you.
The usual daily dose ranges from 20 to 60 mg. The maximum recommended dosage for OCD is 80 mg per day.
Dosage for treatment-resistant depression
For treatment-resistant depression in adults, the usual starting dosage is 20 mg per day. You’ll likely take this dosage for the first several weeks or longer. Then, your doctor may adjust your dosage over time to reach the dose that’s right for you.
The usual daily dose is 20 to 50 mg. The maximum recommended dosage is 50 mg per day.
For this use, Prozac is prescribed together with olanzapine (Zyprexa). Your doctor will recommend the dosage of olanzapine that’s right for you.
Dosage for depression related to bipolar I disorder
For depression related to bipolar I disorder, Prozac’s recommended starting dosage for adults is 20 mg per day. Your doctor may gradually adjust your dosage to reach the dose that’s right for you.
Prozac’s usual daily dose ranges from 20 to 50 mg. The maximum recommended dosage is 50 mg per day.
For this use, Prozac is prescribed together with olanzapine (Zyprexa). Your doctor will recommend the dosage of olanzapine that’s right for you.
Prozac is approved to treat the following conditions in some children:
- depression
- OCD
- depression related to bipolar I disorder, when prescribed with olanzapine (Zyprexa)
The chart below summarizes the usual recommended dosages of Prozac for children.
| Condition | Starting dosage | Maximum dosage |
|---|---|---|
| depression | 10 to 20 mg per day | 20 mg per day |
| OCD | 10 mg per day | 60 mg per day |
| depression related to bipolar I disorder | 20 mg per day | 50 mg per day |
Dosage for depression
For depression in children, Prozac’s usual starting dosage is 10 to 20 mg per day. Your child’s doctor may start by prescribing 10 mg per day and then increase it to 20 mg after 1 week.
Your child’s dosage may need to be adjusted based on their body weight. For more information about possible dosage adjustments, talk with your child’s doctor.
Dosage for OCD
For OCD in children, the usual starting dosage is 10 mg per day. After 2 weeks, your child’s doctor will likely increase their dosage to 20 mg per day. They may raise the dosage over time until they reach the dose that’s right for your child.
The recommended daily dose ranges from 20 to 60 mg.
Dosage for depression related to bipolar I disorder
For depression related to bipolar I disorder, Prozac’s recommended starting dosage is 20 mg per day. Your child’s doctor may gradually increase their dosage over time until they reach the dose that’s right for your child.
The maximum dosage of Prozac for this use in children is 50 mg per day.
For depression related to bipolar I disorder, Prozac is prescribed together with olanzapine (Zyprexa). Your child’s doctor will recommend the dosage of olanzapine that’s right for your child.
Prozac is usually taken once per day in the morning. In some cases, your doctor may recommend that you take Prozac twice per day. For example, if your dosage is 40 mg per day, your doctor may recommend taking 20 mg in the morning and 20 mg at noon.
If you take Prozac with olanzapine (Zyprexa), your doctor will likely recommend taking both drugs at night.
You can take Prozac with or without food.
How long do you take Prozac?
Prozac is usually a long-term treatment. If you and your doctor determine that it’s safe and effective for your condition, you’ll likely take it long term once you reach your maintenance dose.
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Do not take more Prozac than your doctor prescribes, as this can lead to serious side effects.
Symptoms of Prozac overdose
Symptoms caused by a Prozac overdose can include:
- dizziness
- increased blood pressure
- fainting
- slow, fast, or irregular heartbeat or heart rate
- hallucinations (seeing or hearing things that aren’t there)
- confusion
- tremors (shakiness or shaky limbs)
- seizure
- coma
What to do in case you take too much Prozac
Call your doctor right away if you think you’ve taken too much Prozac. You can also call 800-222-1222 to reach America’s Poison Centers or use its online resource. But if you have severe symptoms, immediately call 911 (or your local emergency number) or go to the nearest emergency room.
Here are answers to some commonly asked questions about Prozac’s dosage.
What is the highest dose of Prozac?
The maximum dosage of Prozac is 80 mg per day. But the dosage you’re prescribed will depend on your age and the condition you’re taking Prozac to treat.
For example, the recommended maximum dosage for depression and OCD is 80 mg per day. But for bulimia nervosa and panic disorder, it is 60 mg per day.
Keep in mind that the response to a medication differs between people. This is why it’s important to take Prozac exactly as your doctor prescribes. Your doctor will recommend the right dosage for you.
Do not take more medication than your doctor prescribes. Doing so can increase your risk of serious side effects. (For details, see this article about Prozac’s side effects.)
If you have questions about the maximum dose of Prozac that you can take, talk with your doctor or pharmacist.
Can I avoid side effects such as weight loss if I take a low dose of Prozac?
It depends. Prozac’s side effects, which may include weight loss, can occur with any dose. The risk increases at higher doses. So the risk of side effects, such as weight loss, may decrease with a lower dosage of Prozac.
Always follow the dosage of Prozac your doctor prescribes. They’ll prescribe the lowest dose of Prozac that relieves your symptoms and treats your condition.
If you’re concerned about weight loss with Prozac, talk with your doctor. They may monitor your (or your child’s) weight during treatment with Prozac.
If my Prozac dose increases from 10 to 20 mg, will I have a higher risk of side effects?
It’s possible. Prozac’s side effects can happen with any dose. But higher doses may raise the risk or severity of side effects.
It’s important to note that Prozac has a boxed warning for the risk of suicidal thoughts and behaviors in young adults and children. A boxed warning is the most serious warning from the FDA.
The risk is higher after any dosage changes and during your first few months of treatment. For more details about Prozac’s boxed warning, see the “Boxed warning: Risk of suicidal thoughts and behaviors” section at the beginning of the article.
Be sure to take Prozac exactly as your doctor prescribes. Do not change your dosage without your doctor’s recommendation. To review Prozac’s usual recommended dosages, see the “What is Prozac’s dosage?” section.
If you have more questions about dosage changes and side effects, talk with your doctor.
What’s the dosage of Prozac when it’s taken with olanzapine?
Olanzapine (Zyprexa) is prescribed together with Prozac for certain conditions. These include treatment-resistant depression in adults and depression associated with bipolar I disorder in adults and some children. For both conditions, the usual daily dose of Prozac in adults ranges from 20 to 50 mg. But always take the dosage that your doctor prescribes.
Olanzapine and fluoxetine (the active ingredient in Prozac) are also the active ingredients in the brand-name drug Symbyax. This drug is available as a generic version. Your doctor may prescribe Symbyax for you instead of Prozac and olanzapine together. If your doctor prescribes Symbyax, they’ll recommend the right dosage for you.
Help is out there
If you or someone you know is in crisis and considering suicide or self-harm, please seek support:
- Call or text the 988 Suicide and Crisis Lifeline at 988 or chat at 988lifeline.org. Caring counselors are available to listen and provide free and confidential support 24/7.
- Text HOME to the Crisis Text Line at 741741 to connect with a volunteer crisis counselor for free and confidential support 24/7.
- Not in the United States? Find a helpline in your country with Befrienders Worldwide.
- Call 911 or your local emergency services number if you feel safe to do so.
If you’re calling on behalf of someone else, stay with them until help arrives. You may remove weapons or substances that can cause harm if you can do so safely.
If you’re not in the same household, stay on the phone with them until help arrives.
You may have withdrawal symptoms if you suddenly stop taking Prozac. Withdrawal symptoms are side effects that can occur when you stop taking a drug your body has become dependent on. It’s important to note that dependence is possible even when you take a drug exactly as prescribed.
Prozac withdrawal symptoms can include:
- dizziness
- irritability
- agitation
- anxiety
- feeling of indifference or discontent
- electric shock sensations
- headache
- insomnia
- mood changes
If you and your doctor decide you should stop taking Prozac, they’ll gradually decrease your dosage. This may help decrease the risk of withdrawal symptoms or their severity.
It’s important to follow your doctor’s instructions for stopping Prozac treatment. Your doctor will recommend a schedule that slowly reduces your dosage over time.
Tell your doctor if you have bothersome withdrawal symptoms while stopping Prozac treatment. They may have you temporarily go back to your previous dose or decrease your dosage more slowly.
Note that Prozac takes a while to get out of your system after your last dose. If withdrawal symptoms occur, they may not start right away.
If you have questions about stopping your Prozac treatment or what side effects to expect, talk with your doctor. You can also check out this article for details on tapering off antidepressants.
The sections above describe the usual dosages provided by the drugmaker. If your doctor recommends Prozac for you, they’ll prescribe the dosage that’s right for you. To review Prozac’s usual recommended dosages, see the “What is Prozac’s dosage?” section.
Remember, you should not change your dosage of Prozac without your doctor’s recommendation. Only take Prozac exactly as prescribed. Talk with your doctor if you have questions or concerns about your current dosage.
Here are some examples of questions you may want to ask your doctor:
- How long will I need to wait before any dose changes?
- Does my dosage of Prozac need to change if I’m taking other drugs along with it?
- Will you lower my dosage if I have side effects from Prozac?
- Will my dosage of Prozac need to change if I have kidney problems?
To learn more about Prozac, see these articles:
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Disclaimer: Healthline 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.
