Venlafaxine (Oral)

Venlafaxine is a common antidepressant that allows for more serotonin activity, which positively affects mood.


Branded by Pfizer as Effxor®, Venlafaxine is a common antidepressant. It works by blocking reuptake proteins for serotonin and norepinephrine. This leaves more active transmitters in the synapses. In simpler terms, Venlafaxine allows for more serotonin activity, which positively affects mood. It is used in patients with illnesses like depression and generalized anxiety to improve their mental health and well-being. It is often prescribed in-hand with therapy or counselling to maximize the effects of the drug.

Venlafaxine is often prescribed to patients who do not respond to selective serotonin reuptake inhibitors (SSRIs). It is one of the ten most used antidepressants in the country, ranking number six in a 2007 study. There are over 17 million prescriptions of Venlafaxine within the United States.

Venlafaxine is considered safer and more efficient than many other antidepressants, but it is not considered the first choice for many patients with depression. It is often taken as a second or third resort after trying other forms of antidepressant medication, such as SSRIs like Prozac® or Zoloft®.

Patients considering Venlafaxine should talk to their doctor if they are taking any other antidepressants, experience migraines, or regularly take blood thinners. Patients with bipolar disorder should also discuss other options, as Venlafaxine may adversely affect their condition and cause manic episodes.

Venlafaxine is metabolized into desvenlafaxine, which is sold under the brand name Pristiq®.

Studies show that Venlafaxine may have benefits to patients suffering from PTSD, menopause, or ADHD. However, these effects were marginal, and Venlafaxine should not be the first choice when treating these dilemmas. Its primary use is in treating mental health issues such as depression, anxiety, and other related illnesses.

Conditions Treated

  • Major Depressive Disorder (MDD)
  • Generalized Anxiety Disorder (GAD)
  • Social phobia or Social Anxiety Disorder (SAD)
  • Panic disorder

Type of Medicine

  • Antidepressant (serotonin-norepinephrine reuptake inhibitor)

Side Effects

Venlafaxine may cause a variety of side effects in patients, even if they are regularly and responsibly taking the medication. They can vary from person to person depending on their existing conditions, sensitivity, and other factors. It is recommended that you speak to a doctor if these side effects become a serious issue, as other non-interactive drugs may be prescribed to counteract them.

Some side effects can be controlled and counteracted by over-the-counter or herbal methods, but beware of any possible interactions or scams. Do not trust any untrustworthy marketing, and always contact a doctor before taking a new medication.

A list of common side effects include:

  • Nausea
  • Headaches, or the exacerbation of existing migraine conditions
  • Trouble sleeping or abnormal dreams
  • Excessive sweating
  • Drowsiness

These side effects are common, and may decrease in frequency or disappear entirely as you continue taking the drug. The body requires a certain amount of time to adjust to the addition of new medications or chemicals, and the likelihood of these becoming serious issues are low. However, if they begin to adversely affect your day-to-day life, speak to your doctor as soon as possible.

Less common, mild side effects can include chills, constipation, loss of appetite, heartburn, and dry mouth. These do not warrant medical attention, but if they become an issue, contact your doctor. Every person reacts differently to a new medication, so do not be alarmed if your side effect is not on this list. Other (non-threatening) side effects may occur, so if you experience any number of abnormal changes in how you feel, record them and mention them during your next visit. If they become pressing, contact your doctor.

More serious side effects have been recorded, and may require professional attention. Serious side effects include:

  • Muscle weakness or loss of strength
  • Decrease in libido or an inability to perform sexually
  • Easy bruising and bleeding
  • Severe shaking and tremor

Stop taking your prescription and contact your doctor immediately if you experience any of these side effects. Some patients are not compatible with certain medications, and it is wise to keep an eye on your body in the time after you begin taking Venlafaxine. While these side effects are likely not harmful, they may be a sign that Venlafaxine is not right for you.

Harmful side effects are not common, but they have been recorded. Extreme side effects may include:

  • Chest pain
  • Severe shortness of breath, or a painful cough that does not subside
  • Blood in stool
  • Abnormal vomit (looks like coffee grounds)
  • Seizures
  • Severe, incapacitating headaches

If these side effects occur, stop taking Venlafaxine immediately and contact help. Do not wait to contact your doctor, these are serious side effects that may result in permanent damage or life threatening conditions. While rare, some patients may react badly to Venlafaxine and require medical attention.

There are recorded cases of Venlafaxine causing more serious conditions like Serotonin Syndrome, also known as serotonin toxicity. If you are taking any other drugs that increase serotonin, ask your doctor before taking Venlafaxine. Serotonin Syndrome side effects include:

  • Hallucinations
  • High, unexplained fever
  • Twitching
  • Muscle spasms or twitching
  • Dizziness or loss of coordination

While recorded cases of Serotonin Syndrome under Venlafaxine are rare, they can occur in patients who take medications that increase the levels of serotonin in the brain. Do not take serotonin toxicity lightly, it may become fatal if left untreated.

You are responsible for recognizing harmful side effects after beginning your medication, so do not overlook troubling symptoms if you believe they may have been caused the drug. It is better to be safe than sorry in these situations, so keep a close eye on your body and record any negative side-effects you experience.


Dosage may vary from person to person, and may also be adjusted as time goes on. You may need to increase or decrease the amount and frequency of your medication until the fit is right for you. That being said, it is best to follow your doctor's orders to avoid overdosing. If you experience changes or are dissatisfied with the effects of your dosage, speak to your doctor to discuss your options.

Dosages may change depending on what form of the drug you are taking. Venlafaxine is currently available in immediate-release tablets, extended-release tablets, and extended release capsules. Your dosage may also vary depending on your illness and how severe your symptoms are. Do not attempt to self-medicate yourself.

Here are the regular, adult doses for Venlafaxine, sorted by disorder and form. (Please note: Children and teens should not take Venlafaxine unless recommended by a doctor, and those dosages should be strictly determined by a medical professional.)

For Major Depressive Disorder (MDD):

  • Immediate release: 37.5mg twice a day. Dosage may be adjusted to 25mg three times a day to reduce nausea. Maximum dose is 225mg daily.
  • Extended release: 75mg daily. Maximum dose is 225mg daily.

For Generalized Anxiety Disorder (GAD), and Social Anxiety Disorder (SAD):

  • Extended release: 75mg daily. Maxmimum dose is 225mg daily.

For Panic Disorder:

  • Extended release: 37.5mg daily. Maximum dose is 225mg daily.

Venlafaxine is taken orally in both tablet and capsule form. If you need to increase your dose, speak to a doctor and do it gradually. The usual increase is a steady addition of 75mg per week, but your doctor may ramp up your dosage differently depending on your medical history, sensitivity, condition, or any other drugs you are taking. Do not take more than prescribed when taking Venlafaxine.

Overdoses on Venlafaxine may cause harmful results, life threatening conditions, or even death. Record how much you take per day to avoid accidental overdose, and keep this drug out of the reach of children or teenagers. If you or someone in your household accidentally takes too much, contact poison control immediately.

Overdose symptoms include:

  • Severe drowsiness or loss of consciousness
  • Trouble breathing
  • Fast or irregular heartbeat
  • Seizures

Do not share this medication with others. Venlafaxine should not be the first antidepressant you try. While SNRIs like Venlafaxine have positive affects on patients that do not respond to SSIDs, most patients should try taking SSIDs first, as they are safer and have fewer side effects.

If you are experiencing depression, try therapy or counselling before using antidepressants like Venlafaxine, and try to continue your sessions with a mental health professional even after you begin medication. Venlafaxine should not be given to children or teenagers, as it may cause suicidal thoughts or self harm.

In young adults, additional side effects may be present. If you experience trouble sleeping, mania, feelings of recklessness, or thoughts of suicide/self harm, contact your doctor as soon as possible. Strong, intense feelings of fear, agitation, anger, or anxiety may also be present. Young people may need more time for their hormones to balance before they can properly begin heavy treatment for depression or anxiety.

If you miss a dose of Venlafaxine, take it as soon as possible. If too much time has passed since your last dose, skip that dose entirely and take it at your usually scheduled time tomorrow. Do not double dose, as you may take too much. Keep track of your medication, and contact poison control if you accidentally overdose.


Venlafaxine may interact with other drugs or existing conditions to create adverse affects on a patient's body and mind. Discuss with your doctor before beginning treatment with Venlafaxine, and keep track of any and all herbal/chemical medications you are taking. If you begin taking other drugs while taking Venlafaxine, speak to your doctor before using them.

If you are taking any form of medication that may increase serotonin, speak to your doctor before beginning your first dose of Venlafaxine. Over-increase of serotonin may result in serotonin toxicity, also known as Serotonin Syndrome.

Do not take Venlafaxine with monoamine oxidase (MAO) inhibitors such as Nardil®, Marplan®, or Parnate®. These drugs also have a long half-life, so wait an appropriate amount of time before switching from MAO inhibitors to Venlafaxine. Likewise, wait until all traces of Venlafaxine have been cleared from your system before beginning any prescription of MAO inhibitors.

Venlafaxine lowers the seizure threshold, so drugs like bupropion and tramadol should not be taken in tandem with Venlafaxine. Taking them together may result in an increased risk of seizures, which can possibly result in brain damage or physical injury. If you must take them together, speak to your doctor and do so in low doses.

This medication is not recommended for patients with bipolar disorder, or a history of mania. Venlafaxine may increase the likelihood of manic episodes, exacerbate mania, or even cause episodes in patients suffering from bipolar disorder. This drug is not recommended to treat this condition. If you possibly have bipolar disorder, get a proper diagnosis before beginning treatment for either mental illness.

Patients with renal disease, liver disease, hypertension, and hyponatremia should also discuss with their doctor before taking any form of Venlafaxine, name brand or generic. Large doses of Venlafaxine may also register on drug tests as PCP, so keep a record of your medications to avoid misunderstandings.


Venlafaxine is an antidepressant, and should be used primarily for that purpose. It is not a drug to be taken recreationally. While generic forms of Venlafaxine are prescribed in low doses for other purposes, do not take it without first discussing your options with a medical professional. Venlafaxine is a serious drug that affects chemicals in the brain, and irresponsible self-medication may result in imbalance, harm to the body, mental unwellness, and unwanted side effects.

Do not stop taking Venlafaxine without doctor approval, even if you feel well. Upon stopping your Venlafaxine treatment, you may experience Discontinuation Syndrome or a sharp return of your symptoms. Speak to your doctor before stopping Venlafaxine, and discuss any pressing issues as soon as possible. It is recommended that you go off Venlafaxine by slowly reducing your dose, to lessen or avoid any unpleasant effects.

Doubling up on antidepressants may result in Serotonin Syndrome, a toxicity of the serotonin in your brain. It is not recommended that you take more than one serotonin-affecting drug at a time, as it may increase your risk of Serotonin Syndrome. If you experience hallucinations or other symptoms of serotonin toxicity, stop taking all antidepressants and contact your doctor immediately.

Like many other antidepressants, Venlafaxine may cause suicidal thoughts, thoughts of self harm, and exacerbated depression in children, teenagers, and young adults. They may also experience extreme agitation, aggressiveness, and recklessness. It is not recommended that patients under the age of 18 take this medication, so discuss with your doctor before putting any young person on Venlafaxine.

Patients with bipolar disorder should not take Venlafaxine, as it may cause manic or mixed episodes. In patients with a history of suicide attempts, speak to your doctor before taking your first dose of Venlafaxine.

If you have any recorded history of allergic reactions to Venlafaxine or its metabolized form dedvenlafaxine (Pristiq®), do not take either drug. Allergic reactions include rashes, stomach problems, or various other symptoms. If you experience an allergic reaction, stop taking the medication immediately and contact your doctor. Venlafaxine tablets or capsules may also contain gelatin, iron oxide, cellulose, hypromellose, and titanium dioxide. If you have a recorded allergy to any of these, tell your doctor before beginning any prescription.

If you regularly use blood thinners such as aspirin, other painkillers, or arthritis medications, speak to your doctor before beginning Venlafaxine, as it may result in easy bleeding. Do not continue taking Venlafaxine if you experience blurred vision or drowsiness, especially if you regularly operate large machinery or cars.

Never take Venlafaxine with MAO inhibitors, as it may also cause Serotonin Syndrome. If you must take them within the same year, wait a week or two after stopping your MAO inhibitors before beginning your Venlafaxine treatment. Convulsions, digestive issues, restlessness, fever, and high blood pressure have been recorded when these drugs are taken together.

If you have been taking Venlafaxine for a long period of time, regularly visit your doctor to discuss how it is working for you. If the drug starts to lose efficacy, it may be time to increase your dose or discuss other options. When it comes to taking medications, you are partially responsible for your own health. Do not continue taking Venlafaxine if you experience serious side effects, and do not take your medications recklessly.


Venlafaxine should be stored in a dry, cool place. Heat, moisture, or extended exposure to sunlight may make the drug less effective, or change its chemical components entirely. This medication also should not be frozen, so a room-temperature location is ideal. Venlafaxine should be kept within a marked, child-safe container to avoid accidental consumption by infants, toddlers, or children. Keeping it inside its original prescription bottle is recommended.

If there are teenagers or older children in the house, put your Venlafaxine prescription somewhere out-of-sight and out-of-reach. Accidental consumption can result in adverse effects or even overdose. Contact poison control immediately if you believe they might have consumed any considerable amount of Venlafaxine.

If you find a pill that appears to be Venlafaxine, throw it away, even if you have a prescription. Medication that may have been contaminated should not be taken. Likewise, do not buy Venlafaxine from anyone but your pharmacy. There is no guarantee that you are getting the drug you paid for, and you may be receiving placebos or harmful chemicals.

Do not take medication past its expiration date. Dispose of it properly and get a new prescription. Unused or outdated medication should be disposed of properly, so make sure that no animals or small children can get to the drug after you've thrown it away. Do not dump loose pills into garbage containers or unmarked bags. Keep the medication in its container, and do not give it to anyone else for disposal.

Venlafaxine should not be given to anyone outside of a doctor-prescribed situation. Do not share this drug, sell it, or give it to family members. User discretion is advised.


Introduced in 1993, Venlafaxine has been available in branded and generic forms for over twenty years. It is a chemical medication used to treat of a variety of similar and varied mental illnesses. Patients suffering from Major Depressive Disorder (MDD), Generalized Anxiety Disorder (GAD), social phobia, or panic disorder may benefit from taking this drug. Closely related to other serotonin-norepinephrine reuptake inhibitors (SNIDs), Vanlafaxine is a common and effective treatment.

Patients that do not respond to selective serotonin reuptake inhibitors (SSIDs), may find a valuable and life-improving medication in Venlafaxine. It is designed to improve mood, so that users can continue their life and thrive without being hindered by chemical imbalances in their brain. That being said, teenagers and young adults should be wary of Venlafaxine, and avoid taking it if possible. It may have adverse effects and do the opposite, encouraging thoughts of self harm or suicide.

Venlafaxine is a prescription drug, so speak to your doctor before beginning any treatment involving Effexor® or Venlafaxine's metabolized form Pristiq® (denvenlafaxine). Interactions have been recorded, as well as harmful side effects and allergies. Be aware of your symptoms, and take Venlafaxine responsibly.

Use of Venlafaxine or other antidepressants may result in Serotonin Syndrome, a toxicity of the serotonin in the brain. If you begin to experience symptoms of this condition, stop taking your medication and contact your doctor immediately. Like many other antidepressants, Venlafaxine has risks and side effects that may be harmful to you or your health. However, these reports are rare and most people are able to take this medication safely.

Do not take Venlafaxine if you have any recorded allergies, conflicting medications, or bipolar disorder. Speak to your doctor if you have concerns, and do not hesitate to try other options if you decide Venlafaxine is not right for you. Like any other medication, discretion is advised. Take the medication responsibly, keep it out of the reach of children, and record any troubling side effects or symptoms as they occur.

In many cases, the side effects of Venlafaxine are inconsequential, and the benefits of medication outweigh those of an unmedicated lifestyle. If you suffer from depression, anxiety, social phobia, or panic, contact your doctor to discuss your options. Venlafaxine may not be your first choice, but it is a viable, safe option if you do not respond to other antidepressants.

Last Reviewed:
December 22, 2017
Last Updated:
April 05, 2018
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