10 Dangerous Side Effects of Venlafaxine + Experiences


Venlafaxine is often prescribed for anxiety disorders and depression.

The drug is also known under the brand name Effexor.

Do you often suffer from feelings of anxiety that seem to appear out of nowhere?

Do you know where your fears come from, but fail to overcome them?

Do you want to know what the risks of Venlafaxine are and which side effects it can cause?

Then read this article carefully because this medicine is not without risk.

NB! This article is not intended as medical advice. I wrote it only to inform you about the use of this drug.

Purpose of this article : In this article you will be introduced to Venlafaxine. You will learn what this drug is used for and what the side effects are. You can also read some experiences from others in this article. Finally, you will learn a healthy alternative to never have to take this drug again.

What is Venlafaxine?

Venlafaxine belongs to a group of medicines called serotonin and norepinephrine reuptake inhibitors (SNRIs). This medicine is used to treat depression and anxiety disorders. Venlafaxine or Efexor is mainly prescribed for generalized anxiety disorders, social anxiety disorders and panic disorders .

Neurological research has shown that people who are depressed or anxious have lower levels of serotonin and norepinephrine in the brain.

Neuroscientist  Janna Marie Bas – Hoogendam, researcher at the University of  Leiden , studied the brain structure of family members with social anxiety disorders.

And what turned out? Social anxiety has an influence on the structure of certain brain regions and it is precisely this structure that is hereditary.

Both serotonin and norepinephrine are neurotransmitters. Neurotransmitters are the body’s own chemical elements. They provide communication between nerve cells. Serotonin affects your mood. Noradrenaline stimulates your alertness. 

SNRI  stands for ‘Serotonin and Norepinephrine Reuptake Inhibitor’. This means that these drugs act on these two neurotransmitters.

They give them a helping hand, as it were. This makes you feel less depressed and anxious when you take Venlafaxine.

It is important to know that it takes a while for Venlafaxine to work. Unlike benzodiazepines, you don’t immediately feel the effect of SNRIs.

If you take a medicine such as Tema zepam , for example , you will notice after about half an hour that you become calmer.

This is usually not the case with SNRIs such as Venlafaxine. You will find out in the next section how long it takes for Venlafaxine to work.

How long does it take for Venlafaxine to work?

How long it takes for Venlafaxine to start working depends on what you are using it for.

For depression, anxiety, panic disorders and tension

If you take Venlafaxine, you should notice improvement after about 6 weeks. If this remedy does indeed help you, it is recommended that you continue to use this medicine for 6 months to a year.

If you do not notice any improvement after 6 weeks, it is not much use to continue taking this medicine.

Social phobia

Because social phobia is a fairly complex phobia, it may take a little longer for you to notice an improvement. You must not only get rid of your fears but also find the courage to get back into social situations.

It can take up to 4 months before you notice the effect of Venlafaxine.

It is important that you take this drug consistently for Venlafaxine to work properly. It is also better to always take it at the same time of day.

It is generally believed that SNRIs are safe if you follow your doctor’s prescription.

However, these medicines can cause many side effects. Some side effects are annoying, but quite harmless. Other side effects can be dangerous.

Just like the effect of Venlafaxine, the side effects can also differ from person to person. Want to know more about the side effects of Venlafaxine? Then read on carefully.

Side Effects of Venlafaxine

According to  statistics  from the National Institute for Public Health and the Environment, slightly more than 1 million Dutch people use an antidepressant.

Research has shown that in about 30 to 50% of these users these drugs do not have the desired effect.

Many users spend months looking for the medicine that suits them. These people endure a lot of side effects that are actually not necessary at all.

#1 Gastrointestinal Disorders

Gastrointestinal disorders are very common when you start taking Venlafaxine.

Once your body is used to this drug, these usually go away on their own. Usually these gastrointestinal disorders are quite annoying, but not dangerous.

However, if you have a serious condition such as a stomach ulcer or intestinal disease, Venlafaxine can be dangerous.

#2 Weight gain

The Venlafaxine package leaflet states that you can gain weight as a side effect. This is the case with most SNRIs, by the way. It has even been scientifically proven that SNRIs make you heavier.

Researchers from King’s College London have compared the weight of antidepressant users and those who do not take antidepressants.

People of normal weight took the least amount of antidepressants. More than 25% of the obese patients were taking antidepressants. This study spread over several years.

And it turned out that  the patients who took antidepressants gained more over the course of this period than people who did not take SNRIs.

The conclusion of the  study was that the use of SNRIs could contribute to an obesity epidemic.


It is clear that there is a link between weight gain and SNRIs. Researchers don’t really know exactly why this is the case.

It’s generally believed that if you’re anxious or depressed, you don’t have much of an appetite. When the drug starts to work, you feel better, which also makes you more hungry.

Venlafaxine can lead to obesity and that is actually a cause for concern.

#3 Tiredness and drowsiness

Real fatigue is not very common when taking Venlafaxine. However, you may feel quite drowsy while taking this medicine.

Feeling drowsy can negatively affect your responsiveness.

It is therefore dangerous to perform activities where you have to concentrate optimally. I am thinking mainly of controlling machines or monitoring processes at work.

Even chores around the house can be dangerous if your concentration is not optimal. It becomes all the more dangerous if you are in traffic. Driving is therefore not recommended when using Venlafaxine.

#4 Interaction with alcohol and narcotics

Alcohol and narcotics enhance the effect of Venlafaxine.

Although fatigue with the use of Venlafaxine is not very common, the combination of alcohol and Venlafaxine can make you quite sleepy.

This can of course lead to very dangerous situations at home, at work and in traffic. Never use alcohol or narcotics while taking Venlafaxine!

#5 Feeling rushed, palpitations and shortness of breath

You can feel very restless and excited, especially if you have just started taking Venlafaxine.

This rushed feeling can also cause palpitations and shortness of breath.

If these side effects are very severe, you may think there is something physically wrong with you. And then the outbreak of a panic attack is not far away.

#6 Dizziness, blurred vision and fainting

Earlier I explained to you how antidepressants affect neurotransmitters such as serotonin and noradrenaline.

This often results in unwanted blockages of certain receptors in the central nervous system.

This can cause you to suddenly have low blood pressure after getting up. Such a sudden drop in blood pressure is called orthostatic hypotension in medical terms .

This sudden drop in blood pressure can make you feel dizzy, have blurred vision and even pass out.

#7 Sleep disorders

If you use Venlafaxine, you often sleep less well.

The reason for this is that the amount of serotonin and noradrenaline increase, making your body more active.

The result of a bad night’s sleep is, of course, that you can feel tired during the day.

This reduces your reaction time and your concentration, which can lead to dangerous situations in daily life.

#8 Increase in depressive thoughts

It probably sounds terribly contradictory, but an anti-anxiety drug like Venlafaxine can actually promote depressive thoughts.

It can also make you terribly restless and even aggressive.

Thoughts of suicide or harming yourself may also increase.

Research at the Nordic Cochrane Center has shown that young people in particular are twice as likely to have suicidal thoughts.

#9 Habituation and dependence

As many as 30% of antidepressant users have a hard time getting rid of them.

Once you have started with a drug such as Venlafaxine or Efexor, your body quickly gets used to it.

It is true that most users do not reach for higher doses. The effect of this medicine remains the same over time.

If you want to stop taking Venlafaxine, you may experience intense withdrawal symptoms, especially if you stop taking Venlafaxine abruptly.

That is why it is important to taper off this drug slowly.

#10 Withdrawal Symptoms

If you gradually reduce Venlafaxine, the withdrawal symptoms will be less intense.

However, this does not mean that you cannot suffer from it.

You can experience both physical and psychological withdrawal symptoms. Physical complaints mainly manifest themselves in nausea, insomnia and dizziness.

Yet you can also get complaints such as trembling limbs or the feeling that there are, as it were, ‘spiders crawling under your skin’.

Psychological withdrawal symptoms are mainly irritability, depressive thoughts, fears and even suicidal tendencies.

Taking Venlafaxine or Effexor is not without danger. It is true that people can react very differently to this drug.

I would therefore like to let a few users have their say. By reading their stories you can get a better understanding of the use of Venlafaxine.

Experiences with Venlafaxine

Below 3 users tell about their venlafaxine experiences:

Michele’s story

I have been taking Venlafaxine for 6 years. It all started with a  social phobia  that often caused me to have  panic attacks  . During my puberty I developed such low self-esteem that I completely closed myself off from others. At school I often had panic attacks and decided to terminate my studies prematurely. 

My mother decided it couldn’t go on like this and took me to the doctor. He prescribed me Venlafaxine. This remedy works very well for me: I feel that I am stronger in life and I have also been able to slowly rebuild my self-confidence. Since I have been taking this product I have gained a few kilos, but I am happy to add that. One day I hope to be able to go through life without Venlafaxine again.

Chantal’s story

Four years ago my mother got cancer. I cared for her until the last hours of her life. When she died, my whole world collapsed. Not only had I lost my mother, I suddenly seemed to have nothing to do. I slipped into a deep depression and developed a particularly intense  fear of death . I visited several therapists for this, but therapy alone did not help me. My psychiatrist then prescribed Effexor for me.

 I thought I could overcome all my fears with this. The first 6 weeks everything seemed to be going well. I had some side effects like stomach pain, headache and dizziness, but I could live with that. However, after these 6 weeks I felt more and more depressedbecome. I had anxious dreams and thought the world would be better off without me. I immediately decided to stop taking Effexor. My fears came back and they were much worse than before. After being admitted to a psychiatric clinic, I am now going through life without Effexor.

The story of Senne

My daughter has autism. As a single father, it’s really not easy to deal with. I don’t know how her condition will evolve and that makes me extremely anxious. I have been taking Venlafaxine for 2 years now on the advice of my GP. This drug suppresses my fears but also all other emotions. I find it difficult to give my daughter the love she deserves. This often makes me feel depressed, even though I take Venlafaxine. I would like to find another solution to get rid of my fears, but do not dare to stop with the drug. Once I tried it and I was miserable. I don’t feel well with this medicine, but unfortunately I don’t see any other solution.

As these experiences show, Venlafaxine is not a panacea to get rid of your fears. This is not a drug by the way.

Medicines flatten your emotions, but you won’t be able to overcome your fears with medicines.

If you want to go through life without Venlafaxine, it is important to gradually reduce this drug. If you don’t, you can get very intense withdrawal symptoms.

Weaning off with Venlafaxine

Because suddenly stopping Venlafaxine can be very dangerous, it is important to taper off this drug.

It is best to do this in consultation with your doctor, but I am happy to give you some tips.

#1 Phase-out schedule

If you want to stop taking Venlafaxine, your doctor will suggest a tapering schedule.

Your dose of Venlafaxine will then be reduced slightly each week. Follow this phase-out schedule very closely.

Even if you are having a difficult day, it is important not to reach for a higher dose. Always do this in consultation with your treating doctor!

#2 Duration of tapering off Venlafaxine

Don’t expect every day to be the same.

Even if you gradually taper off Venlafaxine, you may still experience withdrawal symptoms.

However, these will be less intense than if you stop taking this medicine abruptly.

Also keep in mind that it can take up to 8 weeks before you can stop taking this medicine completely.


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