Medically reviewed by Kristin Hall, FNP
Written by Our Editorial Team
Last updated 6/17/2021
If you’ve been diagnosed with depression or one of several common anxiety disorders, you may have been prescribed the medication Effexor®.
Effexor, which is currently sold as Effexor XR® and generic venlafaxine, is a popular medication that’s used to treat depression and several forms of anxiety.
It’s been around for decades and is used by millions of people worldwide.
Research shows that Effexor is an effective treatment for depression and anxiety. However, like with other medications, it usually requires several weeks to start working.
Below, we’ve explained what Effexor is, as well as what it does as a treatment for mental health issues such as depression and anxiety.
We’ve also explained how long it usually takes for Effexor to start working, as well as the steps that you can take to get the best possible results while using Effexor.
Effexor is an antidepressant. It contains the active ingredient venlafaxine and belongs to a class of medications called serotonin-norepinephrine reuptake inhibitors, or SNRIs.
Pfizer, the company that manufactures and sells Effexor, no longer offers the original version of this medication.
Instead, Effexor is currently available in extended-release form under the brand name Effexor XR.
Effexor is also available in generic form as venlafaxine. This version of the medication is sold in several forms under a variety of brand names.
Generic venlafaxine and Effexor XR are prescribed to treat major depressive disorder (MDD, or depression), generalized anxiety disorder (GAD), social anxiety disorder and panic disorder or panic attacks.
SNRIs such as Effexor work by increasing the amounts of serotonin and norepinephrine in your brain and body.
These neurotransmitters play important roles in regulating your mood, feelings of anxiety and level of alertness.
Numerous studies have found that Effexor, either in its original or extended-release form, helps to ease the symptoms of depression and anxiety.
In a review published in the journal CNS Drugs, researchers concluded that venlafaxine XR is an effective treatment for major depression.
They also noted that it helps to lower the severity of anxiety symptoms in depressed people.
A meta-analysis published in the journal PLOS One also found that venlafaxine XR is effective and well tolerated as a treatment for generalized anxiety disorder in adults.
Although Effexor starts working as soon as it’s absorbed by your body, it typically takes several weeks to produce any noticeable changes in your mood, feelings and thoughts.
You may experience some improvement in your appetite, sleep patterns and energy level in the first one to two weeks of using Effexor.
Noticing a positive change in these areas is usually an early sign that the medication is starting to work in your body.
It may take six to eight weeks before you notice improvements in your mood, feelings, thoughts and level of interest in certain activities after starting treatment with Effexor.
If you don’t notice any improvements after using Effexor for eight weeks or longer, it’s important to talk to your healthcare provider.
Keep taking your medication as prescribed, even if you don’t experience any changes in your depression or anxiety symptoms.
Your healthcare provider may suggest adjusting your dosage or making changes to the way you use your medication.
Do not adjust your dosage of Effexor or stop using this type of medication without first talking to your healthcare provider.
Effexor XR and generic venlafaxine come in tablet or capsule form. If you’re prescribed Effexor XR or a generic extended-release venlafaxine, you should take your medication once daily with food.
If you’re prescribed a shorter-acting form of venlafaxine, you may need to take your medication two to three times each day.
Make sure to follow the instructions provided by your healthcare provider and use your medication only as directed.
If your medication comes in capsule form, make sure to take it whole. Do not crush, dissolve or chew the capsule.
It’s common to start Effexor or generic venlafaxine at a low dose, then adjust your dosage over time based on your response to this medication.
It’s important to keep your healthcare provider informed about how you feel so that they can adjust your Effexor dosage appropriately.
For answers to questions such as: Should I increase my Effexor dosage? You can read our guide to Effexor Dosage.
As with other antidepressants, Effexor and generic venlafaxine can potentially cause a range of side effects.
Common side effects of Effexor XR include:
Somnolence (sleepiness or drowsiness)
Erectile dysfunction (ED)
Some of these side effects may improve on their own over time.
If you experience persistent or severe adverse effects after starting treatment with Effexor, it’s important to contact your healthcare provider for assistance.
Although uncommon, Effexor and other antidepressants can potentially cause more severe side effects. We’ve discussed these in our full guide to antidepressant side effects.
As an SNRI, Effexor may interact with other medications, including certain medications used to treat depression and/or anxiety.
Medications that may interact with Effexor include other Serotonin-norepinephrine Reuptake Inhibitors (SNRIs), Selective Serotonin Reuptake Inhibitors (SSRIs), Monoamine Oxidase Inhibitors (MAOIs), lithium, triptans, linezolid, tramadol and St. John’s wort.
In some cases, these interactions may lead to a severe increase in serotonin levels, referred to as serotonin syndrome.
Make sure to tell your healthcare provider about all medications you use or have recently used before you begin treatment with Effexor for anxiety.
Venlafaxine is an effective medication that’s often used to treat depression, generalized anxiety disorder and other forms of anxiety.
Like with similar medications, it’s important to take Effexor correctly to get the best possible results. Make sure to:
Keep using Effexor, even after your symptoms improve. Venlafaxine, the ingredient in Effexor, can control the symptoms of depression and anxiety. However, it isn’t a cure for either of these conditions. Make sure to keep using Effexor, even after you experience improvements. Over time, your healthcare provider may suggest making changes to your Effexor usage based on how you respond to this medication.
Talk to your healthcare provider before stopping Effexor. Like other medications for depression and anxiety, Effexor can cause withdrawal symptoms (commonly referred to as antidepressant discontinuation syndrome) if it’s stopped abruptly. If you want to stop taking Effexor, talk to your healthcare provider first. They may advise you to gradually reduce your dosage of Effexor to prevent withdrawal symptoms.
If you don’t notice improvements, let your healthcare provider know. Not everyone responds to antidepressant medications in the same way. While some people notice improvements from Effexor, others may notice little or no change in their mood, feelings and thoughts. If you don’t experience any improvements after using Effexor or generic venlafaxine for eight weeks, talk to your healthcare provider. They may adjust your dosage or provide a different type of medication for you to use.
Effexor is a common medication that helps to control depressive symptoms, generalized anxiety disorder, social anxiety disorder and panic disorder.
It usually takes one to two weeks for Effexor to produce a noticeable improvement in your sleep patterns, energy level and appetite.
This is often an early sign that the medication is working.
After using Effexor for six to eight weeks, many people notice a difference in their general mood, feelings, thoughts and level of interest in certain activities.
If you don’t notice any changes after using Effexor for eight weeks or longer, it’s best to let your healthcare provider know.
You may need to adjust your dosage of Effexor or, if you don’t notice any improvements at all, use a different type of medication to treat depression or anxiety.
Depression and anxiety are common issues that can affect anyone.
If you have concerns about your mental wellbeing and want to improve your quality of life, you can talk to a licensed mental health provider online by scheduling an online psychiatry evaluation using our mental health services.
We also offer venlafaxine (the active ingredient in Effexor) online, following a consultation with a licensed psychiatry provider.