Medication Guide
Venlafaxine (Effexor XR) Side Effects and Uses
A plain-language guide to Venlafaxine, an SNRI antidepressant. Learn how it helps, what it treats, how to take it and which side effects to know about.
Quick answer. Venlafaxine (Effexor XR) is an SNRI antidepressant. Common venlafaxine side effects include nausea, more sweating, dry mouth and trouble sleeping or feeling sleepy. The rare but serious ones, and when to get help, are listed under venlafaxine side effects below. Never stop or change your dose on your own.
How Venlafaxine Can Help You
Venlafaxine (Effexor XR) is a serotonin and norepinephrine reuptake inhibitor, or SNRI. It is approved for depression and several anxiety disorders. At lower doses it acts mostly on serotonin. At higher doses it adds more norepinephrine activity. That can help energy, focus and drive.
So it is a common next step when an SSRI has helped only part of the way.
Early changes may show up within one to two weeks. The fuller effect on mood and anxiety usually builds over four to eight weeks. Response often improves as the dose goes up. So your prescriber may raise it over several weeks. Blood pressure and side effects are checked along the way.
Uses for Venlafaxine
- Major depressive disorder
- Generalized anxiety disorder (extended-release form)
- Social anxiety disorder (extended-release form)
- Panic disorder (extended-release form)
- Post-traumatic stress disorder (off-label)
- Menopausal hot flashes (off-label)
- Migraine prevention (off-label)
How to Take Venlafaxine
Your prescriber decides your dose and how it changes. The extended-release form is taken once a day with food. Take it at about the same time each day. Swallow it whole. Many people take it in the morning. If it makes you drowsy, your prescriber may suggest the evening.
Try not to skip doses. Venlafaxine leaves the body quickly. Even one missed day can bring dizziness, nausea or brain zaps. Missed a dose? Take it when you remember, unless the next dose is close. Never double up. Do not stop venlafaxine on your own. A slow taper planned by your prescriber is essential.
Venlafaxine Side Effects
Common Side Effects
- Nausea, mostly early on
- More sweating
- Dry mouth
- Trouble sleeping or feeling sleepy
- Dizziness
- Constipation
- Lower appetite
- Sexual side effects, such as lower desire or delayed orgasm
Serious: Get Medical Help Promptly
- New or worse suicidal thoughts, mostly in people under 25 (boxed warning)
- Blood pressure that stays high, more likely at higher doses
- Serotonin syndrome, with agitation, fever, fast heartbeat or stiff muscles
- Strong stopping symptoms if doses are missed or it is stopped suddenly
- Unusual bleeding or bruising
- Mania, with a very high or irritable mood
What Is Venlafaxine Used For?
Venlafaxine is the generic name for Effexor and Effexor XR. It belongs to a group of antidepressants called SNRIs. The FDA has approved it for major depressive disorder. The extended-release form is also approved for three anxiety disorders. They are generalized anxiety, social anxiety and panic disorder.
Venlafaxine comes in two main types. Immediate-release tablets are usually taken two or three times a day with food. Extended-release capsules and tablets are taken once a day. They release the medicine slowly, which keeps levels steady. The two types are not swapped one for one. Any change goes through your prescriber.
When to Take Effexor and Why It Can Make You Sleepy
There is no single best time of day for everyone. The label says to take the extended-release form once a day with food. Take it at about the same time, morning or evening. A steady routine matters more than the exact hour. Venlafaxine leaves the body quickly.
Venlafaxine affects sleep in different ways. Some people feel sleepy or tired. Others have trouble falling asleep or have vivid dreams. These effects are often strongest in the first weeks. Do not drive until you know how it affects you. Ask your prescriber before changing your dose time.
Interactions to Know About
Venlafaxine must never be taken with an MAOI antidepressant. A waiting period is needed when switching between the two. The same goes for linezolid, an antibiotic. It also goes for methylene blue given by IV. Your prescriber plans any switch so the two never overlap.
Other drugs that raise serotonin can lead to serotonin syndrome with venlafaxine. Examples are other antidepressants, triptans for migraine, tramadol, lithium and St. John's wort. Aspirin, ibuprofen and naproxen can raise the chance of bleeding. So can blood thinners such as warfarin. Alcohol is best avoided because it can worsen mood and add to drowsiness.
Before You Start Venlafaxine
Tell your prescriber about high blood pressure, heart problems, glaucoma and seizures. Also mention kidney or liver disease. Also share any personal or family history of bipolar disorder. In some people with bipolar disorder, an antidepressant taken alone can trigger mania. So this history changes the plan.
Like all antidepressants, venlafaxine has a boxed warning. It covers suicidal thoughts and behavior in children, teens and young adults. Watch for mood changes in the first months and after any dose change. If you are thinking about harming yourself, call or text 988, or call 911. Are you pregnant, planning a pregnancy or breastfeeding? Then talk it through with your prescriber first. Read about anxiety care by telehealth in California.
Is Venlafaxine Right for You?
Only a full evaluation with a prescriber can tell you if Venlafaxine fits your symptoms, history and goals. Harpal Singh, PMHNP-BC offers psychiatric evaluations and ongoing medication management by telehealth anywhere in California.
SCHEDULE AN APPOINTMENT CALL (888) 457-8124
Related Medication Guides
Other guides in the same group, written the same simple way. Being in one group does not mean you can swap one medicine for another.
- Trazodone (Desyrel), Serotonin modulator (SARI) antidepressant
- Vilazodone (Viibryd), SSRI and serotonin partial agonist antidepressant
- Vortioxetine (Trintellix), Serotonin modulator antidepressant
- Amitriptyline (Elavil), Tricyclic antidepressant (TCA)
- Bupropion (Wellbutrin XL), Atypical antidepressant (norepinephrine-dopamine reuptake inhibitor)
- Citalopram (Celexa), SSRI antidepressant
FAQ
Questions About Venlafaxine
Is Effexor the same as venlafaxine?
Yes. Venlafaxine is the generic name and Effexor is the brand name. Effexor XR is the long-acting version, and its generic works the same way. Your pharmacy label may show either name.
How is venlafaxine different from an SSRI?
Venlafaxine raises both serotonin and norepinephrine. SSRIs work on serotonin alone. The norepinephrine effect grows at higher doses. It can help with energy, drive and focus, and it gives your prescriber more room to adjust treatment.
Is venlafaxine good for anxiety or just depression?
Both. The extended-release form is FDA approved for depression and for three anxiety disorders. They are generalized anxiety, social anxiety and panic disorder. Many people with both anxiety and depression do well on it.
Why does Effexor make me so sleepy?
Drowsiness is a known side effect of venlafaxine, and it is often strongest in the first few weeks. For some people it eases as the body adjusts. If it lasts or makes daily life hard, tell your prescriber, who may suggest a different dose time or another option.
Why do I sweat so much on venlafaxine?
More sweating is one of the more common side effects of SNRIs, including venlafaxine. It can happen day or night and does not always fade on its own. Let your prescriber know if it bothers you, since there may be ways to help.
How long do Effexor side effects last?
Many early side effects, such as nausea and dizziness, often ease within the first couple of weeks. Others, such as sweating or sexual side effects, may continue while you take it. Keep a simple note of what you notice and bring it to your follow-up.
Why does my prescriber check my blood pressure?
At higher doses, venlafaxine can raise blood pressure. Checks from time to time, mostly after dose increases, catch this early. If it rises, your prescriber may lower the dose or switch medicines.
What are brain zaps and will I get them?
Brain zaps are brief electric-shock feelings that can happen when venlafaxine levels drop fast, such as after a missed dose or a sudden stop. They are unsettling but not dangerous. Taking your dose every day and tapering slowly prevents them for most people.
Is venlafaxine addictive?
Venlafaxine is not a controlled substance and does not cause cravings. Your body does adjust to it, though, so stopping suddenly can bring dizziness, nausea and other stopping symptoms. That is why your prescriber plans any stop with a slow taper.
What if I have side effects at a higher dose?
Tell your prescriber. Many side effects can be managed by raising the dose more slowly, changing the timing or settling at a lower dose that still works. Never change or stop the medicine on your own, since sudden changes cause stopping symptoms.