Prozac To Treat Anxiety: All You Need To Know

Generalized anxiety disorder (GAD) is a common condition that affects 3.1% of the US population¹. Up to one in five adults² (20%) suffer from an anxiety disorder

Women are more likely³ than men to be affected by anxiety. One study⁴ found that the chances of developing any type of anxiety disorder over a lifetime were 30.5% for women and 19.2% for men. 

A report by the World Health Organization (WHO)⁵ in 2017 found that anxiety was the sixth most common disorder causing significant disability in people’s lives in highly developed countries. 

If you struggle with anxiety, you may be prescribed Prozac to help to control your symptoms. Prozac is a well-known antidepressant, but it can also be effective in treating anxiety disorders. 

Have you considered clinical trials for Anxiety?

We make it easy for you to participate in a clinical trial for Anxiety, and get access to the latest treatments not yet widely available - and be a part of finding a cure.

What is an anxiety disorder?

Experiencing occasional anxiety is normal, but when your symptoms start to interfere with your daily functioning, you may have an anxiety disorder. 

Some symptoms that you may experience if you have an anxiety disorder include:

If you struggle with an anxiety disorder, you may find that you have excessive and persistent worry or fear about everyday situations. You may have repeated episodes of intense fear and anxiety (panic attacks) that may be so severe it can feel as though you are having a heart attack. 

You may also find that you start changing your lifestyle to avoid situations or activities that trigger your anxiety

When you have panic attacks that are so severe that you become too scared to leave the house, you may be struggling with a disorder known as panic disorder with agoraphobia. 

When are you diagnosed?

According to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-V), to be diagnosed with an anxiety disorder, your symptoms must: 

  • Have been present for at least six months 

  • Result in significant distress or impairment in social and occupational areas 

  • Not be attributable to a physical cause such as an overactive thyroid 

Symptoms of an anxiety disorder often start in childhood or adolescence⁶ and continue into adulthood. 

Different types of anxiety disorders

There are different types of anxiety disorders, including generalized anxiety disorder, social anxiety disorder, specific phobias or fears, and panic disorder (panic attacks). 

Take a look at the classification below and see which category your anxiety disorder belongs to.

Generalized anxiety disorder

  • Persistent, excessive worry about routine events or situations

  • Disproportionate worry that is difficult to control

  • Your anxiety impacts your ability to function


  • Fear of being in places or situations that may cause you to feel trapped, helpless, or embarrassed 

  • Avoidance of situations or places that cause you to feel trapped, helpless, or embarrassed

  • In severe cases, you may feel too afraid even to leave home

Panic disorder, with or without agoraphobia

  • Repeated episodes of intense fear, worry, or terror that reach a peak within a few minutes

  • Associated with physical symptoms such as shaking, shortness of breath, sweating, nausea, and heart palpitations

  • Physical symptoms can be so severe that you believe you are having a heart attack or are about to die

  • You may develop a fear of having further panic attacks

Social anxiety disorder

  • High levels of anxiety or fear around social situations

  • Feeling abnormally self-conscious in the company of others

  • May lead to avoidance of social situations

  • Disproportionate fear or concern about being judged negatively by others

Childhood anxiety disorders

These childhood anxiety disorders include separation anxiety and selective mutism.

  • Present in childhood

  • May sometimes continue into adulthood

  • Interfere with school and/or social functioning

Anxiety disorder caused by a medical condition

This kind of anxiety can be triggered by an underlying medical condition such as an overactive thyroid. Usually, you would have symptoms of anxiety and the underlying medical condition.

Substance-induced anxiety disorder

The symptoms of this disorder include intense feelings of anxiety or panic related to taking or misusing certain drugs or medications.

Specific phobias

  • Major anxiety on being exposed to a certain trigger or situation

  • Avoidance of your specific trigger

  • You may experience panic attacks in response to your trigger

Causes of anxiety disorders

The exact cause of anxiety is not fully known. It is likely that these disorders are caused by a combination of factors, including both your genes and your environment.

Genetics are known to play a role in the development of anxiety disorders. You are more likely to develop this condition if you have a blood relative who suffers from it.

There is evidence to suggest that an imbalance in the neurotransmitters in your brain² may play a role in the development of anxiety disorders. People with low serotonin activity and elevated noradrenergic system activity may be more prone to developing anxiety.  

The following factors have been identified as putting you more at risk of developing an anxiety disorder:

  • Trauma

  • Stress as a result of ill health

  • Excessive or persistent life stressors

  • Some personality types that may be more prone to developing anxiety disorders

  • Drug or alcohol use or misuse

  • Other mental health disorders such as depression or substance abuse

Treatment of anxiety

Anxiety disorders are mainly treated with medication and psychotherapy, such as cognitive behavior therapy. Lifestyle modifications, including exercise and mindfulness practice, can also be part of your treatment regimen.

Prozac is a commonly prescribed medication for the treatment of anxiety. Let’s take a deeper look at what Prozac is and how it works.

What is Prozac?

You may recognize the name Prozac because it was the first SSRI to be registered for the treatment of depression in the United States. It can also be effective in treating anxiety. 

The active ingredient in Prozac⁷ is fluoxetine. Fluoxetine belongs to a class of drugs called selective serotonin reuptake inhibitors (SSRIs). Since low serotonin activity is thought to be a contributing factor to anxiety, it makes sense that a drug that works on the serotonin system would be used in the treatment of anxiety. 

How does Prozac work?

SSRIs work by affecting the activity levels of neurotransmitters in the brain. Neurotransmitters are chemical messengers that relay messages between brain cells (neurons). 

Serotonin is one of the most well-known neurotransmitters. It has a role in feelings of well-being and happiness, thinking, memory, sleep, digestion, and circulation.

Serotonin is released by neurons. Some of the serotonin that is released attaches to other neurons, where it passes on its message.

The remaining “leftover” serotonin is reabsorbed by the neuron that initially released it. This process is called reuptake. Anxiety is thought to occur when there is an imbalance in the production and reuptake of serotonin.

Prozac works by preventing the reuptake of serotonin, and this results in more free serotonin⁸ available to attach to other neurons. 

The only anxiety disorder that Prozac has FDA approval⁷ for is panic disorder, with or without agoraphobia. This is because randomized controlled trials have demonstrated that fluoxetine is effective in treating panic disorder⁹.

Prozac is used off-label for the treatment of social anxiety disorder.

How long does Prozac take to work?

Before starting treatment for anxiety, it is important to know that SSRIs can take anywhere between two to six weeks⁹ to start taking effect.

Prozac usually takes between four to six weeks to kick in, so you should not expect to feel better immediately after starting treatment.

You may even feel worse⁹ for the first couple of weeks after taking Prozac. You may experience increased jitteriness and other anxiety symptoms. For this reason, your doctor may start you on a low dose and titrate the dose up as your body becomes used to it.

Alternatively, your doctor may prescribe another medication, such as a benzodiazepine, to concurrently take with Prozac for the first two weeks of treatment.

Side effects of Prozac

As with any medication, Prozac does have the potential to cause some side effects⁷, including the following:

  • Insomnia

  • Nausea

  • Diarrhea

  • Decreased appetite

  • Dry mouth

  • Headache

  • Jitteriness

  • Yawning

  • Decreased libido

  • Excessive sweating

  • Weight loss/gain

  • Decreased orgasm

  • Tremors

The good news is that many of these side effects are dose-dependent⁸. If you do experience them, speak with your doctor before giving up on the medication. Simply lowering your dose may allow your side effects to resolve.

Most of the side effects of Prozac are immediate. Unfortunately, this means that you will experience the adverse effects first before the beneficial effects of the medication. 

However, as with most SSRIs, the side effects diminish with time. You may find that any side effect you experience may resolve after a few weeks of treatment. 

Other serious side effects

Some less common but more severe side effects¹⁰ of Prozac are:

  • Serotonin syndrome

  • Suicidal thoughts and/or behavior

  • Blurred vision, tunnel vision, eye swelling, and pain

  • Low blood-salt levels (more common in elderly people⁸)

If you experience any of these symptoms, you should see your doctor immediately. 

Serotonin syndrome is a rare but potentially life-threatening condition characterized by excessive sweating, shivering, incoordination, muscle spasms, and altered levels of consciousness. 

What dose of Prozac is used for anxiety?

Prozac is registered for use in the treatment of panic disorder with or without agoraphobia. Your doctor will tailor your treatment to suit you, but the recommended dosing¹⁰ is as follows:

Initial dose

The initial dose is 10 mg orally once a day, increased after one week to 20 mg orally once a day.

Starting at a lower dose helps minimize the potential for side effects and decreases the initial worsening of anxiety symptoms that can accompany starting an SSRI.

Maintenance dose

After the initial dose, you may be given the maintenance dose, which is 20 mg to 60 mg orally per day. Your doctor may consider increasing the dose if you aren’t feeling better after several weeks.

Maximum dose

The maximum dose for Prozac is 60 mg orally per day. Doses greater than 60 mg have not been studied in clinical trials for the treatment of panic disorder.

Prozac is also used for social anxiety disorder, but there are no studies to support specific dosing since this is off-label.

It is generally recommended that you take Prozac in the morning because it can cause insomnia. 

When and how to stop taking Prozac

Once Prozac has started working, your doctor will likely recommend that you stay on it for a period of at least six to twelve months¹¹. When you do decide to stop taking it, do it gradually, not cold turkey. 

Stopping Prozac suddenly can lead to serotonin discontinuation syndrome⁸, which is the result of your body trying to readjust to no longer being under the influence of SSRI activity. 

Its symptoms include dizziness, nausea, fatigue, drowsiness, headache, anxiety, and agitation. Because of the long half-life of fluoxetine (it takes a long time to be entirely removed from your system), the symptoms of discontinuation syndrome for Prozac are far milder than for other SSRIs. 

How safe is it to take Prozac?

Prozac is generally considered safe for long-term use and is not addictive.

The lowdown

Prozac (active ingredient: fluoxetine) is a commonly prescribed SSRI for anxiety. Prozac takes between two and six weeks to take effect and needs to be continued for at least six months to a year. It is generally considered a safe medication for long-term use and is not addictive. 

When you decide to stop taking Prozac, make sure to do so under the guidance of your doctor. Although it doesn’t cause severe discontinuation syndrome, it’s still safer to taper the dose down when you stop taking it.

Have you considered clinical trials for Anxiety?

We make it easy for you to participate in a clinical trial for Anxiety, and get access to the latest treatments not yet widely available - and be a part of finding a cure.

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