How Long Do Anxiety Medications Take To Work? Here’s What You Need To Know

Generalized Anxiety Disorder (GAD) is a common condition that affects 3.1% of the US population.¹ Women are 1.5 to 2 times more likely² to suffer from anxiety than men. One study³ found that lifetime prevalence rates for any type of anxiety disorder were 30.5% for women and 19.2% for men. 

A report⁴ by the World Health Organization (WHO) in 2017 found that anxiety disorders were the sixth most common disorders that cause significant disability in people’s lives in highly developed countries. 

Fortunately, there is treatment available for anxiety disorders. Read on to find out all you need to know about which types of medication are effective for anxiety and how they work. 

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.

When should you treat your anxiety?

Anxiety is treated with psychotherapy (such as cognitive behavioral therapy), pharmacotherapy (medication), or a combination of the two. Evidence⁵ suggests that anxiety disorders can often go untreated or are not treated effectively. Generally, it is recommended to seek treatment for your anxiety symptoms if they:

  • Are persistent

  • Result in difficulty socializing

  • Interfere with your ability to work

  • Cause you significant distress

  • Cause depression or suicidal thoughts

  • Cause you to use or misuse alcohol or other drugs to self-treat your anxiety

Although the exact causes of anxiety are not entirely understood, evidence suggests that an imbalance in neurotransmitters within the brain may play a role in the development of anxiety disorders.

If you have low serotonin activity and elevated noradrenergic system activity, you may be more prone to developing anxiety. Anxiety medication, therefore, helps to balance out your neurotransmitters.

Types of anxiety medication and their effectiveness

There are many different types of medicines used to treat anxiety, including:

  • Serotonin reuptake inhibitors (SSRIs)

  • Serotonin noradrenaline reuptake inhibitors (SNRIs)

  • Benzodiazepines

  • Pregabalin

  • Tricyclic antidepressants

  • Buspirone

The most commonly used medications to treat anxiety are selective serotonin reuptake inhibitors (SSRIs) and serotonin noradrenaline reuptake inhibitors (SNRIs). Both types of medication work by increasing neurotransmitter levels in your brain, and they tend to take between two to six weeks to reach full effectiveness. Initially, both types of medication can make your symptoms worse before they get better.

Selective serotonin reuptake inhibitors (SSRIs)

SSRIs work by increasing levels of serotonin in your brain. Serotonin acts as a messenger (neurotransmitter) to carry signals between brain cells. Usually, serotonin is reabsorbed by your brain cells at a certain rate. SSRIs slow down the rate of reabsorption of serotonin by neurons, leaving more serotonin available to improve the transmission of messages between your brain cells.  

Examples of SSRIs include:

  • Escitalopram

  • Citalopram

  • Sertraline

  • Fluoxetine

  • Paroxetine 

When you start taking an SSRI, it’s very important to know that they do not reduce your symptoms immediately. It can take between two and six weeks for SSRIs to start working. 

In the first two weeks of SSRIs treatment, your anxiety symptoms may worsen, and you may feel more jittery than usual. Your doctor may initially start you on a lower dose to prevent this and gradually increase it to an effective dose. Alternatively, they may start you on a combination of benzodiazepine and SSRI to help you adjust to the SSRIs.

As with any medication, you may develop side² effects² while taking SSRIs. Some side effects, such as nausea, will go away when your body adjusts to the medication. 

You are likely to experience worse side effects in the first two weeks of taking SSRIs. Tolerability to different SSRIs varies between patients and drugs, so you may experience side effects with one type of SSRI but not with another. 

Some of the more common side effects of SSRIs include:

  • Nausea

  • Jitteriness

  • Restlessness

  • Headaches

  • Fatigue

  • Increased or decreased appetite

  • Weight gain

  • Weight loss

  • Tremor

  • Sexual dysfunction

  • Diarrhea

Once your anxiety symptoms are under control, your doctor will likely suggest that you stay on your SSRI medication for at least six months, and possibly longer, depending on the severity of your anxiety and your circumstances. 

When you are ready to discontinue treatment, you will need to be weaned off your SSRI slowly to prevent any withdrawal effects. 

Serotonin noradrenaline reuptake inhibitors (SNRIs)

SNRIs work by increasing the levels of serotonin and noradrenaline in your brain. They do this by blocking the reabsorption of serotonin and noradrenaline by brain cells, leaving more serotonin and noradrenaline available to transmit messages between neurons. 

Examples of SNRIs include:

  • Venlafaxine

  • Desvenlafaxine

  • Duloxetine

  • Levomilnacipran 

As with SSRIs, it can take between two to six weeks before you start seeing any improvement in your anxiety symptoms. Your anxiety may initially feel worse before getting better. For this reason, your doctor may start you on a lower dose, gradually increasing it as you are able to tolerate the medication better. Alternatively, they may start you on a combination of a benzodiazepine and SNRI to help you adjust.

Side effects of SNRIs are typically at their worst just after starting treatment and generally subside within a week or two. Common side effects include:

  • Nausea

  • Jitteriness

  • Restlessness

  • Headache

  • Appetite changes

  • Weight gain or loss

  • Sweating

  • Sexual dysfunction

  • Diarrhea

  • Urination problems

  • Constipation

Once your anxiety symptoms are under control, your doctor will likely suggest that you stay on your SNRI medication for at least six months and possibly longer, depending on your anxiety severity and personal circumstances. When you are ready to discontinue treatment, you will need to be weaned off your SNRI slowly to prevent any withdrawal effects.

Other anxiety medications

If SSRI or SNRI treatment is not working for you, your doctor may suggest an alternative medication, or they may combine another drug with your existing SSRI or SNRI treatment.


Benzodiazepines are commonly used to treat anxiety. Approximately 55% to 94% of patients with anxiety are treated with benzodiazepines in the US. 

Unlike SSRIs and SNRIs, benzodiazepines quickly reduce anxiety symptoms as they take effect after the first dose. This makes them effective at controlling panic attacks.  

However, benzodiazepines often come with adverse side effects, including: 

  • Fatigue

  • Dizziness

  • Decreased level of consciousness

  • Increased reaction time

  • Impaired driving skills

  • Impaired cognitive function

Benzodiazepines also carry a high risk of addiction and dependence, especially in people who have a history of substance abuse. For this reason, benzodiazepines are not recommended as first-line therapy or for long-term use and should be used only as necessary under the guidance of your doctor. 

Benzodiazepines can be used in the short term when initially starting SSRI or SNRI treatment to minimize or counteract the increase in anxiety symptoms as your body adjusts.


Pregabalin is another medication used as a second-line treatment for anxiety when SSRIs or SNRIs are ineffective. Pregabalin was initially developed to treat epilepsy and nerve pain. However, it has been shown⁶ to be effective for treating anxiety, especially GAD. Pregabalin has a rapid onset of action,⁶ similar to benzodiazepines, as it starts working in less than a week. 

There is some concern that pregabalin may have the potential to be abused,² so it is not recommended for people with a history of substance abuse. 

If you are taking pregabalin for anxiety but want to stop, make sure to speak with your doctor before doing so, as sudden discontinuance can lead to withdrawal symptoms. 

Tricyclic antidepressants

Tricyclic antidepressants (TCAs), such as imipramine and clomipramine, can also help with anxiety. However, they are not as commonly used because they have significant side effects and are less effective than SSRIs and SNRIs. 

TCAs are moderately effective in treating anxiety, but because they are not as well tolerated as SSRIs and SNRIs, they are not as commonly prescribed as a first-line treatment. 


Buspirone is an anxiolytic medication that has been shown to be effective⁷ in treating anxiety, especially GAD, as a second-line treatment. Buspirone does not tend to become addictive, but it only takes effect after two and four weeks. Because of this, it is not effective for the acute treatment of severe anxiety or panic attacks.

The lowdown

If your anxiety negatively impacts your quality of life, you may want to consider starting treatment for it. Various anti-anxiety medications have been effective in treating anxiety, such as SSRIs, SNRIs, benzodiazepines, pregabalin, TCAs, and buspirone. The medications vary in their effectiveness, the time they take to start working, and side effects, so make sure to discuss which medication is right for you with your doctor.

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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