Effexor Side Effects Guide

Kristin Hall

Reviewed by Kristin Hall, FNP

Written by Geoffrey C. Whittaker

Published 10/31/2022

Updated 07/08/2021

Depression is a complex mental health disorder with a variety of mild and severe side effects. It also takes a variety of forms, from manageable to completely debilitating. 

It can affect every aspect of how you feel, how you live your day-to-day life, your relationships, your career, etc. 

As such, treating it is neither a one-size-fits-all proposition nor is it always as easy as “take this pill.”

Effexor® may be an effective medication for you. It may be an effective medication for a friend or family member, but not for you. 

Likewise, it may produce side effects with varying severity, which will be different from person to person. 

Our guess is that you’re here to find out what taking this medication might do to the rest of your life — and whether the side effect risks are worth it. 

To answer that question, we need to share some more information first. Let’s start with the basics.

Let’s start with a simple definition for depression

The National Institute of Mental Health (NIMH) says that depression is a mood disorder characterized by recurring patterns of feeling empty, sad, down or of losing interest in daily activities — the stuff you care about. 

If that sounds familiar, you may be suffering from depression. 

But there are different kinds of depression. 

Some forms like Seasonal Affective Disorder (SAD) occur only at certain times — typically during the colder months when natural light and other environmental mood brighteners are at annual lows. 

In contrast, major depression has no boundaries. It affects all aspects of a person’s life (sleeping, working, eating, etc.) and usually does so for a period of at least two weeks, but often longer.

After a certain point, ongoing depression gets a different name. Persistent depressive disorder is the one that can really feel never ending. It is typically characterized by a low mood lasting two years or more. 

Why does depression happen? Well, we don’t know exactly. 

Research suggests that various biological, genetic, psychological and environmental factors may impact depression, but none of these has been confirmed as a root cause. 

Like causes, symptoms of depression can vary person to person, though people will typically show a variety of mood issues like anger, exhaustion or irritability when depressed. 

Depression can also lead to sleep issues, make you engage in reckless behavior and substance abuse and it can cause you to lose interest in things you like (sex, sports) or cause your weight to fluctuate. 

It can even give you suicidal thoughts and can even cause physical symptoms like stomach issues. 

Effexor, which is the brand name version of a drug called venlafaxine hydrochloride, is a serotonin and norepinephrine reuptake inhibitor, or SNRI. 

Serotonin and norepinephrine are both neurotransmitters: serotonin manages mood and norepinephrine manages stress responses. 

SNRIs are a form of antidepressant, which are medications designed to breach the blood-brain barrier and impact chemical balances to treat mood disorders.

Effexor is specifically prescribed to treat major depressive disorder (MDD), generalized anxiety disorder (GAD), social anxiety disorder (SAD) and panic disorder.

Off-label uses for Effexor include treating attention deficit hyperactivity disorder (ADHD), post-traumatic stress disorder (PTSD), obsessive compulsive disorder (OCD) and other disorders, as well as hot flashes, premenstrual dysphoric disorder (PMDD), migraines and diabetic neuropathy.

Effexor can be taken in two formats: a once-daily extended release tablet, and an instantaneous tablet generally taken two to three times per day. 

It may take a couple of months for extended release to show effects, as it must build up in your system like many other antidepressant medications. You can find more information in our guide on how long it takes Effexor to work.

Immediate release tablets come in 25mg, 37.5mg, 50mg, 75mg and 100mg doses. Effexor XR capsules (extended release) are typically prescribed in 37.5mg, 75mg and 150mg formats.

Effexor is generally considered safe and effective as an antidepressant, but that doesn’t mean there are no side effects. 

In most cases, side effects are considered mild, but patients taking Effexor should look out for some common and more serious potential reactions. 

Common Side Effects of Effexor

While Effexor is generally well tolerated, common side effects tend to fit into one of several categories. 

You may experience issues with sleeping, gastrointestinal issues, sedation and cardiovascular side effects. Sexual function may also be impaired.

Common side effects may include:

  • Headache 

  • Nausea

  • Diarrhea

  • Dry mouth

  • Increased sweating

  • Nervous feelings

  • Dizziness

  • Stomach pain

  • Heartburn

  • Loss of appetite

  • Weight loss

  • Nightmares

  • Uncontrollable shaking. 

If you experience any of these side effects, it’s best to talk to your healthcare provider about them immediately — and especially if they worsen. 

Some of these side effects can be mitigated by a lower dose, so your healthcare provider may alter your prescription if you’re having continuing issues.

Serious Side Effects of Effexor

Serious side effects should be brought to a healthcare provider’s attention without delay. In some cases, these issues and complaints may be a result of overdose or too high of a dosage. 

Call your healthcare provider if you experience: 

  • Rash

  • Hives

  • Itching

  • Seizures

  • Chest pain

  • Unusual bruising or bleeding

  • Fever

  • Eye pain or redness

  • Confusion

  • Problems with coordination or hallucinations.

Rare Side Effects of Effexor

In rare cases, the most serious side effects can include exacerbation of depression issues, serotonin syndrome, mania, issues with platelet function and can also increase suicidality.

In the most serious cases, rare side effects might also include coma. And left unmanaged, many of the more common side effects, interactions and dosage complications can potentially lead to death. 

In case you’re reading about Effexor for a child, it should be noted that children should be monitored carefully when using this medication, as Effexor can slow growth and weight gain and, in some cases, permanently stunt growth.

It’s also important to note that Effexor does come with a black box warning, as well. 

Per the FDA label for Effexor, this means that there may be an increase in suicidal thoughts or behaviors in children and adolescents who take it, to the point where it’s not approved for pediatric patients.

online mental health assessment

your mental health journey starts here

You should speak with a healthcare professional before taking effexor if you are already taking any monoamine oxidase inhibitors (MAOIs), linezolid and methylene blue. 

Effexor should be used with caution alongside any SSRIs or SNRIs, or any medications that increase serotonin levels.

Weight loss drugs like phentermine should not be taken when using Effexor, as it could result in a nasty mixture of symptoms: excessive weight loss, serotonin syndrome and potentially serious heart problems.

Medications like cimetidine can raise blood pressure and increase the risk of liver disease. Zolpidem, lorazepam and diphenhydramine mixed with Effexor can lead to increased sedation. 

Effexor can also lessen the effectiveness of beta blockers like metoprolol. It can also cause occasional false positives in amphetamine and PCP urine tests for several days, even after the medication is discontinued.

A quick note: it’s recommended that Effexor be taken with food, and not consumed with alcohol. Mixing Effexor and alcohol could cause adverse effects.

Combining this medication and alcohol can lead to increased sedation, and the same goes for an empty stomach.

Pregnant? Read more on our guide on Effexor(venlafaxine) and pregnancy

As you might suspect, there is more to treating depression than pills. While we’re not knocking antidepressants at all, they’re even more effective alongside other treatments, including therapy. 

Therapeutic practices can provide a lot of benefits to people suffering from anxiety. 

Well-known therapy forms like Cognitive Behavioral Therapy (CBT) help patients by giving them a system for recognizing dysfunctional thought patterns — the negative and counterproductive stuff — so that they can be controlled, and the patient can be conscious of how those patterns are affecting them.

Psychotherapy generally might make use of techniques like mindful meditation, which helps you interpret thoughts and feelings in the moment, without passing judgement on yourself. 

Mindfulness practice may involve breathing exercises, guided imagery, and other practices to relax and reduce stress in the body and mind.

Lifestyle changes may also be directed at the discretion of a healthcare professional. 

Common examples might include focusing on improving your weight, your diet, your blood pressure, increasing your exercise and reducing your substance use (this stuff is good for your whole body — not just the depressed parts). 

And there’s science to back this up. Starting an exercise regimen has been shown to be as effective as medication in some cases. 

Despite the potentially worrisome list of side effect warnings, the simple answer is that for most people, Effexor is a safe and effective medication that promises to treat depression.

But you need to be vigilant if using it — that means keeping an eye on your side effects. 

Because the drug is prescribed in two formats (immediate  release and extended release), it also means that you may have to monitor your timing and intake of the medication.

Taking too many or skipping doses of any medication is dangerous, and Effexor and its generics are (like every medication) most effective when used as directed. 

psych meds online

psychiatrist-backed care, all from your couch

Whether you’re about to take Effexor, or another prescription antidepressant, or you’re just getting started on your mental health journey, we have some resources for you to check out. 

If you’re just learning about depression treatments, check out our guide to the types of therapy and our mental health resources guide.

But don’t stop at reading. 

We can’t stress this enough. Depression is a difficult disorder to suffer through, and the longer you wait, the harder it becomes to dig out. 

Talk to someone. Get the help you deserve. If you’re ready to do that now, consider scheduling an online psychiatry evaluation today.

9 Sources

Hims & Hers has strict sourcing guidelines to ensure our content is accurate and current. We rely on peer-reviewed studies, academic research institutions, and medical associations. We strive to use primary sources and refrain from using tertiary references.

  1. U.S. National Library of Medicine. (n.d.). Venlafaxine: MedlinePlus Drug Information. MedlinePlus.
  2. Venlafaxine (Effexor). National Alliance on Mental Illness. (n.d.).
  3. Depression Basics. (n.d.). Retrieved January 08, 2021, from
  4. Craft, L. L., & Perna, F. M. (2004). The Benefits of Exercise for the Clinically Depressed. Primary care companion to the Journal of clinical psychiatry, 6(3), 104–111.
  5. Goyal M, Singh S, Sibinga EMS, et al. Meditation Programs for Psychological Stress and Well-being: A Systematic Review and Meta-analysis. JAMA Intern Med. 2014;174(3):357–368. doi:10.1001/jamainternmed.2013.13018 Retrieved from
  6. Ng, C. W., How, C. H., & Ng, Y. P. (2017). Managing depression in primary care. Singapore medical journal, 58(8), 459–466.
  7. Singh D, Saadabadi A. Venlafaxine. [Updated 2020 Nov 3]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan-. Available from:
  8. The Food and Drug Administration. (2017). EFFEXOR XR® (venlafaxine Extended-Release) Capsules.
  9. Sansone, R. A., & Sansone, L. A. (2014). Serotonin norepinephrine reuptake inhibitors: a pharmacological comparison. Innovations in clinical neuroscience, 11(3-4), 37–42. Available from:

This article is for informational purposes only and does not constitute medical advice. The information contained herein is not a substitute for and should never be relied upon for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment. Learn more about our editorial standards here.

Kristin Hall, FNP

Kristin Hall is a board-certified Family Nurse Practitioner with decades of experience in clinical practice and leadership. 

She has an extensive background in Family Medicine as both a front-line healthcare provider and clinical leader through her work as a primary care provider, retail health clinician and as Principal Investigator with the NIH

Certified through the American Nurses Credentialing Center, she brings her expertise in Family Medicine into your home by helping people improve their health and actively participate in their own healthcare. 

Kristin is a St. Louis native and earned her master’s degree in Nursing from St. Louis University, and is also a member of the American Academy of Nurse Practitioners. You can find Kristin on LinkedIn for more information.

Read more

Care for your mind,
care for your self

Start your mental wellness journey today.