Prozac For Anxiety: Dosage, Side Effects, Interactions & More

By Zina Semenovskaya, MD
Medically reviewed
July 28, 2021

Anxiety is a normal human emotion, but when someone suffers from intrusive, intense anxiety symptoms that impacts their daily life, they have an anxiety disorder.

Anxiety disorders are the most common mental health condition in the United States. By some estimates, more than 40 million Americans, or 18% of our population, will have an anxiety disorder at some point in their lives. 

Fortunately, there are several prescription medications available for patients who need help managing their symptoms. Prozac (fluoxetine) is one of several antidepressant medications that can be a great option for treating anxiety. 

Prozac has been FDA-approved for the treatment of major depressive disorder (MDD), obsessive compulsive disorder (OCD), and depressive episodes related to bipolar I disorder in both adults and children. It is also approved for adults suffering from panic disorder, bulimia nervosa, and treatment-resistant depression.

It can also sometimes be prescribed for social anxiety disorder (SAD), premenstrual dysphoric disorder (PMDD), generalized anxiety disorder (GAD), and post-traumatic stress disorder (PTSD).

In this article, I’ll explain what Prozac is, and how it works for anxiety. I’ll outline the dosage of the drug used for anxiety, how quickly it works, and whether it works for social anxiety.

I’ll explain whether teenagers can take the drug, and how adults and children should take it. I’ll also describe the drug’s side effects, list possible drug interactions and warnings, and lay out the risks of taking Prozac. Finally, I’ll discuss other options that are available if this medication isn’t right for you.

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What is Prozac?

Prozac (fluoxetine) is one of a class of antidepressant medications called selective serotonin reuptake inhibitors (SSRIs), which work by increasing the level of serotonin in the brain. 

Serotonin is a neurotransmitter that passes messages between nerve cells and positively influences our emotions, appetite, and sleep, among other things. In a normal situation, once it has conveyed its message, serotonin is reabsorbed back into the brain.

When someone takes an SSRI like Prozac, however, the drug blocks their brain from reabsorbing—”reuptaking”—serotonin, leaving more available for continued use.

Prozac was brought to market as a brand-name prescription in the late 1980s after the Food and Drug Administration (FDA) approved it to treat patients who had clinical depression.

Since that time, the FDA has additionally approved Prozac to treat major depressive disorder (MDD), bulimia nervosa, and certain anxiety disorders.

Additionally, it is sometimes combined with other medications to treat patients who have bipolar disorder or who struggle with a kind of major depression that is otherwise treatment-resistant.

Does Prozac Work for Anxiety?

Prozac does not cure anxiety disorders, but it is considered a safe and effective way to help patients manage their anxiety-related symptoms. It has been FDA-approved to treat patients with:

  • Panic disorder: An anxiety disorder that causes patients to suffer from regular, spontaneous, and extreme bouts of fear or terror called panic attacks
  • Obsessive-compulsive disorder (OCD): An anxiety disorder in which patients struggle with intrusive thoughts or sensations (called obsessions) and develop repetitive behavioral patterns—called compulsions—in an ineffective attempt to stave them off.

Clinical trials are still testing Prozac’s efficacy with anxiety disorders that it has not been FDA-approved to treat. In the meantime, mental health professionals will often prescribe the drug “off-label” to help address conditions like generalized anxiety disorder (GAD), social anxiety disorder (SAD), persistent depressive disorder, and post-traumatic stress disorder (PTSD).

Directing patients to take off-label medication is legal and safe, as long as the doctor uses their professional discretion. 

How Does Prozac Work for Anxiety?

Prozac is widely considered an effective, first-line treatment option for people who suffer from certain types of anxiety disorders.

By increasing the availability of serotonin in the brain, the drug helps improve mood, regulate emotions, increase quality sleep, and boost appetite. These changes, in turn, can help calm the nervous system and make it less reactive.

Mental health professionals often prescribe SSRIs like Prozac because they are less likely to have serious side effects than other medications.

In addition, when used on its own or in conjunction with other treatments like psychotherapy, Prozac can help anxious patients relax and enjoy a higher quality of life.

Prozac Dosage for Anxiety

Every patient is different. Individual dosages can vary depending on the person taking the medication, their general health, age, and the nature of their anxiety disorder. 

  • Obsessive-compulsive disorder (OCD): It is recommended that most patients with OCD should begin by taking 20 mg of Prozac by mouth every day. If your doctor believes you would benefit from a higher dose, they will gradually increase it by 20 mg over every few months. As a rule, patients should not take more than 80 mg by mouth a day when treating OCD.
  • Panic Disorder: It’s recommended that most patients with panic disorder should begin by taking 10 mg of Prozac by mouth every day before their dose is gradually increased to 20 mg and beyond. Patients with panic disorders should not take more than 60 mg by mouth a day to treat their condition. 

Prozac is also approved for pediatric patients over the age of 7 with obsessive-compulsive disorder.

Most pre-adolescent children should begin taking 10 mg of medication by mouth every day before their dosage increases to 20 mg after two weeks of treatment, while adolescents may be prescribed doses as high as 60 mg daily.

If you or your child has anxiety and are wondering what dosage might help manage those symptoms, please seek medical advice from a healthcare professional.  

How Quickly Does Prozac Work?

If you began to take Prozac recently and have yet to feel its effects, don’t worry. Like other antidepressant medications, you have to take Prozac for some time before you begin to feel better.

While some patients report a decrease in their anxiety symptoms after just a few weeks of regularly taking the medication, most do not experience relief until 6 to 8 weeks into their treatment.

It’s important to remember that once you start Prozac, it can cause withdrawal symptoms if you abruptly stop taking it. If you have been taking Prozac for a while and don’t feel like it is helping you, make an appointment with your doctor—but continue taking the medication as prescribed until you see them.

Once they medically evaluate you, your doctor may recommend a higher dose to make the Prozac more effective for you, or they may gradually taper off the medication to help you avoid withdrawal while changing to a different treatment.

Does Prozac Work for Social Anxiety?

Currently, Prozac is only FDA-approved to treat two specific anxiety disorders: obsessive-compulsive disorder and panic disorder. Anecdotal evidence suggests that Prozac also works to help patients with a social anxiety disorder (SAD) when prescribed “off-label,” but scientific research is still inconclusive. Some studies suggest that Prozac is an effective treatment for people who struggle with social phobias, while others have found that the medication is no more helpful than a placebo.

Can Teenagers be Treated with Prozac?

Many children and teens with anxiety and depression find that Prozac helps them manage their symptoms safely. Prozac is FDA-approved to treat patients ages 7-18 with obsessive-compulsive disorder and pediatric patients ages 8-18 who have major depressive disorder (MDD).

If you or someone you know is taking Prozac or another SSRI like sertraline hydrochloride (Zoloft), you should be aware that for a small number of pediatric patients, these medications can cause an increase in suicidal thoughts and behaviors.

If you or your loved one is showing any indication that they pose a risk to themselves or others, call 9-1-1 or immediately go to the nearest emergency room.

How to Take Prozac

Prozac is available in four forms: a tablet, capsule, time-release capsule, and oral solution. Whatever form your prescription comes in, be sure to take your dosage precisely as directed and only once a day.

You can take your medication in the morning, afternoon, or evening, as long as it’s around the same time every day. Prozac can be taken with or without food.

Side Effects

It’s estimated that 80% of patients experience at least one side effect while taking an antidepressant. Most of these effects are mild, and most patients are not bothered enough by their symptoms to stop taking their medication. 

People who take Prozac can experience a range of common side effects, including: 

Many patients who take Prozac have also reported sexual side effects, including sexual dysfunction (impotence), abnormal ejaculation, decreased libido, and other sexual problems.

In rare cases, patients can have an allergic reaction to Prozac. If you are taking the medication and begin to experience hives, shortness of breath, facial swelling, heat, or skin rash, seek emergency medical attention immediately.

Interactions

Prozac can interact with a variety of other prescription medications, over-the-counter medications, and homeopathic remedies.

To avoid adverse drug interactions, be sure to tell your doctor about everything you take before beginning to take Prozac or any other antidepressant.

Drugs that interact poorly with Prozac include:

  • Anticonvulsants
  • Antipsychotics
  • Benzodiazepines
  • Monoamine oxidase inhibitors (MAOIs)
  • NSAIDs including aspirin and warfarin
  • Olanzapine
  • Pimozide
  • St. John’s wort
  • Thioridazine
  • Tricyclic antidepressants 
  • Tryptophan

Never take Prozac with another SSRI or serotonergic medication. Taking multiple drugs that boost your serotonin levels can put you at risk for developing serotonin syndrome, a rare but severe condition that can cause tremors, palpitations, muscle rigidity, agitation, confusion, and seizures.

If you experience any of those symptoms, go to the emergency room right away as serotonin syndrome can be a life-threatening condition.

Warnings

Prozac is not for everyone. For a small segment of the population, it can contribute to adverse health outcomes, including: 

  • Increased risk of suicide
  • Allergic reaction 
  • Mania or hypomania 
  • Significant weight loss 
  • Abnormal bleeding 
  • Worsening anxiety 
  • Insomnia 
  • Impaired Judgement

If you are taking Prozac and are worried about any physical or mental challenges that you believe might be caused or exacerbated by the medication, call your doctor to share your concerns.

If it is an emergency, dial 9-1-1 or go to your nearest hospital immediately.

Risks

Women who are pregnant or breastfeeding, or become pregnant while taking Prozac, should talk to their doctor about the risks involved.

The medication poses some rare but serious risks to unborn and nursing children, and the risks and benefits should be discussed with your doctor as well as your obstetrician-gynecologist (OB-GYN).

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Other Options 

If you suffer from an anxiety disorder and find that Prozac is not the right option for you, don’t worry. There are other treatments that you can use to manage your symptoms and improve your quality of life. They include: 

  • Selective serotonin reuptake inhibitors: Prozac is only one of many SSRIs approved to treat people with anxiety. Doctors can also prescribe paroxetine (Paxil) and sertraline hydrochloride (Zoloft) for specific anxiety disorders. 
  • Benzodiazepines: Doctors commonly prescribe sedative medications like diazepam (Valium), alprazolam (Xanax), and lorazepam (Ativan) to help patients with anxiety challenges.

You can start controlling your anxiety and get access to the treatment you need with K Health. Starting at $19/month, get prescriptions for mental health medications plus unlimited doctor visits through the K Health app. Start your free assessment here.

Frequently Asked Questions

Can Prozac make anxiety worse?
When most people with anxiety disorders like OCD and panic disorders take Prozac, they find that it helps them manage their symptoms and improve their quality of life. However, in rare cases, the medication can cause adverse side effects, including increased anxiety or nervousness.
Is 10 mg of Prozac enough for anxiety?
Everyone is different, and individual dosage depends on who is taking the Prozac, their age, and the nature of their condition. For some, 10 mg is an effective dose of medication. Others may need to talk to their doctor about gradually increasing their dosage until they get to a dose that’s effective for them.
K Health articles are all written and reviewed by MDs, PhDs, NPs, or PharmDs and are for informational purposes only. This information does not constitute and should not be relied on for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment.

Zina Semenovskaya, MD

Dr. Semenovskaya specializes in emergency medicine, and received her medical degree from Weill Cornell Medical College. She is currently the medical director at Remote Emergency Medicine Consulting, LLC and splits her time working clinically as an emergency medicine attending in California and Alaska. She is the first of our doctors to be fluent in Russian.