Does Effexor-induced brain fog go away? (3+ tips)

In this article, We will be discussing the brain fog that is commonly associated with the use of Effexor and ways to manage it. We will also provide insight into the research studies done on Effexor.

Does Effexor-induced brain fog go away?

Yes, as your body gets used to the medication, some of the side effects, like brain fog caused by Effexor, will go away. Effexor is an antidepressant belonging to the class of selective serotonin reuptake inhibitors (SNRI), which increases the level of serotonin, norepinephrine and, to some extent, dopamine (1)

Fluctuations in these neurotransmitters can cause cognitive impairment, such as changes in mood, memory, perception, concentration and attention, which contribute to brain fog.

Effexor typically takes about two weeks to start working. However, the timeline can vary for each individual. At the beginning of the treatment, Effexor may cause brain fog in some individuals, which typically subsides after 3-4 weeks as the body adjusts to the medication.

If you experience persistent brain fog after taking Effexor, even after several months, seek medical help for further management. Also, avoid discontinuing the medication without consulting a healthcare professional, as it may worsen your condition.

What does the research suggest?

Research says that antidepressants which block serotonin reuptake can have an effect on cognitive functions, which may cause changes in alertness and memory. (2)

There are fewer studies done on venlafaxine associated with brain fog. However, many studies have shown that venlafaxine has a positive effect on cognition, which is impaired in mental illnesses such as depression and anxiety. (1)

The most common adverse reactions caused by Effexor were nausea (30.0%), drowsiness (15.3%), dry mouth (14.8%), sweating (11.4%), abnormal release (9.9%), anorexia (9.8%), constipation (9.3%), impotence (5.3%) and a decreased libido (5.1%). (3)

What are the factors contributing to Effexor-induced brain fog?

Factors contributing to Effexor-induced brain fog are as follows.

Individual sensitivity: The side effects of Effexor vary from person to person. While some individuals may experience brain fog, others may not.

Dose: Higher doses of Effexor are more likely to cause brain fog than lower doses.

Onset of action: It may take time for your body to adjust to the medication, and you may experience some side effects. However, the side effects subsides once your body gets used to the medication.

Withdrawal symptoms: Sudden discontinuation of Effexor can cause withdrawal symptoms, which include cognitive impairment. It is important to consult a physician before stopping the medication.

Drug interaction: Effexor can interact with other antidepressants, antipsychotics, and over-the-counter drugs, contributing to side effects. It is important to talk to your healthcare provider before taking any medication.

Pre-existing conditions: Individuals with underlying mental illnesses such as ADHD, anxiety, schizophrenia, Tourette syndrome, etc can cause brain fog. It is important to identify the cause of brain fog before treating it.

Hormonal fluctuations: In women, fluctuation in hormones occurring during menstruation, menopause, or pregnancy can affect cognitive functions.

Thyroid issues: Hypothyroidism and Hyperthyroidism can have certain effects on cognition and cause brain fog.

Fatigue: Chronic fatigue, lack of sleep and stress can also contribute to experiencing cognitive dysfunctions.

Nutritional deficiency: Not having enough nutrient-rich food can lead to deficiencies, which can hinder bodily processes, and you may develop symptoms such as brain fog.

What to do if Effexor-induced brain fog does not subside?

If you think that the brain fog is caused by Effexor and is not subsiding even after a month. Here are a few steps you can take.

  • Inform your physician about the side effects you are experiencing, explain it in detail and do not hold back.
  • If the side effect is not subsiding, your physician may change your drug or reduce the dose of your medication. Adjustment in your dosage should be done under a physician’s guidance to avoid further side effects.
  • Other antidepressants, such as selective serotonin reuptake inhibitors (SSRIs), tricyclic antidepressants, etc., can be used to treat your mental illnesses.
  • Address underlying causes of brain fog, such as stress, lack of sleep, fatigue, nutritional deficiencies, and other medical conditions.
  • In addition, along with drug therapy, consider psychotherapy, such as cognitive behavioural therapy. Psychotherapy can help address issues contributing to your symptoms.

How to manage Effexor-induced brain fog?

There are some general strategies you can follow to manage Effexor-induced brain fog:

  • Adjust the timing of the dose; if you are experiencing drowsiness or dizziness when you take Effexor, take it in the evening instead of the morning to mitigate the side effects.
  • Stay hydrated throughout the day, as dehydration can contribute to cognitive dysfunction.
  • Regular exercise, such as walking or cycling, helps manage stress, positively affecting cognition.
  • Maintain a healthy diet with proper nutrition, and make sure you get enough nutrients from your food. Consume food which is rich in omega-3 fatty acids.
  • Have a regular sleep schedule, and practice relaxation techniques before bedtime.
  • Try participating in cognitive activities such as puzzles, memory exercises or meditation to help your cognition.


In my opinion, brain fog caused by Effexor should subside within a few days of treatment as your body gets used to the medication. If you are experiencing side effects for a longer duration, ensure you seek medical advice. Avoid abrupt discontinuation of the drug, as it may worsen your condition.

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Singh D, Saadabadi A. Venlafaxine. [Updated 2022 Oct 10]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from:


Siepmann T, Mueck-Weymann M, Oertel R, Kirch W, Pittrow D, Siepmann M. The effects of venlafaxine on cognitive functions and quantitative EEG in healthy volunteers. Pharmacopsychiatry. 2008 Jul;41(04):146-50. Available from:


Effexor [package insert]. Philadelphia: Wyeth Pharmaceuticals Inc; 2017. Available form

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