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Effexor (venlafaxine hydrochloride)

What Are The Risks and Side Effects Associated with Effexor?

  • Possible life-threatening serotonin syndrome when used with  triptan medicines:  See FDA Alert [07/2006] above.
  • Suicidal thoughts or actions: Persons taking Effexor may be more likely to think about killing themselves or actually try to do so, especially when Effexor is first started or the dose is changed.  People close to persons taking Effexor can help by paying attention to changes in user’s moods or actions.   Contact your healthcare professional right away if someone using Effexor talks about or shows signs of killing him or herself.  If you are taking Effexor yourself and you start thinking about killing yourself, tell your healthcare professional about this side effect right away.
  • Stopping Effexor: Do not stop taking Effexor suddenly because you could get side effects.  Your healthcare professional will slowly decrease your dose.
  • High blood pressure and heart problems: You may get high blood pressure or a faster heartbeat.
  • Bleeding problems:Effexor may cause bleeding problems.
  • Mania: You may become unusually hyperactive, excitable or elated.
  • Seizures:  You may experience a seizure (convulsion), even if you are not taking Effexor close in time with a MAOI.
  • Pregnancy: Tell your healthcare professional if you are or may be pregnant because babies delivered to mothers taking Effexor late in pregnancy have developed problems, such as difficulty breathing and feeding.
  • Weight loss: Effexor can cause weight loss.
  • Sexual problems: You may have problems with impotence (erectile dysfunction), abnormal ejaculation, difficulty reaching orgasm, or decreased libido (sexual desire).
  • Other side effects include nausea, sleepiness, dry mouth, dizziness, difficulty sleeping and constipation.
  • Tell your healthcare professional about all your medical conditions, especially if you have liver, kidney, or heart disease, or glaucoma.  Tell your healthcare professional if you are breast-feeding or plan to breast-feed your baby.

Are There Any Interactions With Drugs or Foods?

  • Effexor may interact with medicines other than the ones already mentioned in this information sheet.  These interactions can cause serious side effects. Tell your healthcare professional about all medicines, vitamins, and herbal supplements you take.
  • If you plan to drink alcohol, talk to your healthcare professional.

How Do I Take Effexor?

  • Effexor is taken by mouth, with food, exactly as prescribed by your healthcare professional. 
  • Swallow Effexor XR capsules whole. Do not crush or chew them. You may open the capsule, sprinkle the contents on a spoonful of applesauce, and take right away without chewing. Then follow with a glass of water.

It can take up to 4 to 6 weeks for Effexor’s full effects to be felt.

Effexor (venlafaxine hydrochloride)

Donald Black, MD

APA Reference
Black, D. (2020). Effexor (venlafaxine hydrochloride). Psych Central. Retrieved on September 27, 2020, from
Scientifically Reviewed
Last updated: 29 Jul 2020 (Originally: 17 May 2016)
Last reviewed: By a member of our scientific advisory board on 29 Jul 2020
Published on Psych All rights reserved.