Information About Venlafaxine, Sold As Effexor (US) or Efexor (UK)

Are you taking, or considering taking, Venlafaxine (Effexor) for depression, anxiety, or another mental health reason? This page provides information on the medication’s benefits, side effects, and other properties.

Type of Medication: SNRI

Venlafaxine is a structurally novel Serotonin-Norepinephrine Reuptake Inhibitor which is chemically unrelated to other antidepressants. (See “Drug Action Mechanisms”.)

Variants include Effexor, Effexor XR, Efexor, Efexor XL.

Benefits of Venlafaxine (Effexor, Efexor) for Depression and Anxiety

Venlafaxine is widely prescribed to treat depression, generalized anxiety disorder, and social anxiety disorder (social phobia). The United States FDA has not approved Venlafaxine for paediatric use (see FDA non-approval information – PDF).

Side Effects of Venlafaxine (Effexor, Efexor)

Please note that the following side effects include only some of the most common and somewhat less common but do not include rarer side effects; the list is not exhaustive. Many people taking Venlafaxine (Effexor, Efexor) experience none of these side effects. Please consult a physician about any unusual symptoms.


Some of the more common side effects of Venlafaxine (Effexor, Efexor) include:

  • nausea
  • headache
  • drowsiness
  • dizziness

Less Common

Some of the less common side effects of Venlafaxine (Effexor, Efexor) include:

  • insomnia
  • hypotension (low blood pressure)
  • weight gain
  • wheeziness
  • sexual dysfunction

Venlafaxine (Effexor, Efexor) and Alcohol

The product insert for Effexor (linked below) suggests that “Although Venlafaxine has not been shown to increase the impairment of mental and motor skills caused by alcohol, patients should be advised to avoid alcohol while taking Venlafaxine” (p. 16).

Stopping Venlafaxine (Effexor, Efexor): Discontinuation Effects or Withdrawal Symptoms

It is best to consult a physician before discontinuing Venlafaxine (Effexor, Efexor). Stopping taking Venlafaxine (Effexor, Efexor) may cause discontinuation effects, including (from the Effexor product insert, p. 40):

  • agitation
  • anorexia
  • anxiety
  • confusion
  • coordination impairment
  • diarrhoea
  • dizziness
  • dry mouth
  • dysphoric mood
  • fasciculation (muscular twitching)
  • fatigue
  • headaches
  • hypomania
  • insomnia
  • nausea
  • nervousness
  • nightmares
  • sensory disturbances (including shock-like electrical sensations)
  • somnolence (drowsiness)
  • sweating
  • tremor
  • vertigo
  • vomiting

In addition, one very rare side effect, which Effexor’s manufacturer calls “withdrawal syndrome”, is that the patient, once acclimatized to Effexor, is unable to discontinue taking the drug. With this discontinuation effect apparently permanent, the patient is “hooked for life”.

Should You Buy Venlafaxine (Effexor, Efexor) Online?

Particularly in the United States, many individuals choose to purchase medications online, either for reasons of cost savings, privacy, or both. Both brand-name Effexor and so-called ‘generic Effexor’ (i.e., Venlafaxine without the Effexor brand name) can sometimes be purchased at deep discounts (and sometimes without a prescription) in this way. Before undertaking any purchase of medications online, however — and certainly if you are contemplating doing so without a prior prescription — please consider the integrity of the supplier and the national and/or local laws which may apply where you live.

Information Sources and Disclaimer

The information provided here has been summarized in good faith purely for educational purposes. It is not intended in any way to replace the advice of a qualified medical professional. Please do not take any action on the basis of information contained here without consulting a physician. Unless otherwise specified, information is intended to apply only to adult use of the medication. Drug interaction precautions have not been included; please consult another source for this information.

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Information sources:

All clinical material on this site is peer reviewed by one or more clinical psychologists or other qualified mental health professionals. This specific article was originally published by on and was last reviewed or updated by Dr Greg Mulhauser, Managing Editor on .

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