Effexor Side Effects
Several different side effects can occur with the use of Effexor. Common side effects include nausea, headache, drowsiness, and dry mouth. Uncommon side effects of Effexor, occurring in less than 1 percent of people, can include seizures, liver problems, or hair loss. Serious side effects that you should report to your healthcare provider include aggressiveness, chest palpitations, and difficulty sleeping.
As with any medicine, side effects are possible with Effexor® (venlafaxine hydrochloride). However, not everyone who takes the drug will experience side effects. In fact, most people tolerate it well. If side effects with Effexor do occur, in most cases, they are minor and either require no treatment or can easily be treated by you or your healthcare provider.
(This article covers many, but not all, of the possible side effects with Effexor. Your healthcare provider can discuss a more complete list of Effexor side effects with you.)
Common Side Effects of Effexor
Effexor has been studied thoroughly in clinical trials. In these studies, side effects are always documented and compared to side effects that occur in another group of people not taking the medicine. This way, it is possible to see what side effects occur, how often they appear, and how they compare to the group not taking the medicine.
Based on these studies, the most common side effects of Effexor include:
- Nausea -- in up to 58 percent of people
- Headache -- up to 26.1 percent (see Effexor and Migraine Headaches)
- Drowsiness -- up to 23 percent
- Dry mouth -- up to 22 percent (see Effexor and Dry Mouth)
- Dizziness -- up to 23.9 percent
- Insomnia -- up to 22.5 percent (see Effexor and Insomnia)
- Nervousness -- up to 21.3 percent
- Loss of appetite -- up to 17 percent
- Body weakness -- up to 16.9 percent
- Sweating -- up to 19.3 percent
- Constipation -- up to 15 percent
- High blood pressure (hypertension) -- up to 13 percent
- Ejaculation problems -- up to 12.5 percent (see Effexor Sexual Side Effects)
- Anxiety -- up to 11.2 percent
- Shakiness (tremors) -- up to 10.2 percent
- Diarrhea -- up to 8 percent
- Yawning -- up to 8 percent
- Chills -- up to 6.8 percent
- Vomiting -- up to 6.8 percent
- Indigestion (dyspepsia) -- up to 6.7 percent
- Impotence (erectile dysfunction or ED) -- up to 6 percent (see Effexor and Impotence)
- Blurred vision -- up to 6 percent.
Other common Effexor side effects (occurring in 1 to 6 percent of people) include but are not limited to:
- A decreased sex drive (libido)
- Flushing (redness of the skin, especially the face)
- Weight loss (see Effexor and Weight Loss)
- Weight gain (see Effexor and Weight Gain)
- Abnormal dreams
- High cholesterol
- Unusual thoughts
- Increased urination
- Taste changes.