Cymbalta (Duloxetine): Uses, Dosage, Side Effects, and More

By Jenell Decker, MD
Medically reviewed
February 7, 2020

Cymbalta (duloxetine) is a medication used to treat depression, anxiety, and chronic pain. Most people who take Cymbalta are taking it to treat symptoms of anxiety or depression, which include persistent worry or sadness, loss of interest in things that used to bring them joy, sleep and digestive issues, fatigue, muscular tension and pain, and inability to participate in daily life activities.

Cymbalta is also used to treat conditions that cause chronic pain, like fibromyalgia, arthritis, and diabetic neuropathy. It eases symptoms of chronic pain, anxiety, and depression by increasing available levels of mood-regulating neurotransmitters in the brain.

What Is Cymbalta?

Cymbalta is a prescribed medication that is used to treat depression, anxiety, and chronic pain. Cymbalta belongs to the family of medications called serotonin and norepinephrine reuptake inhibitors (SNRIs), which affect mood, stress, digestion, and pain perception by increasing levels of the neurotransmitters serotonin and norepinephrine in the brain.

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Cymbalta Generic Name

Cymbalta is a brand name for the generic drug called duloxetine. Cymbalta was developed in 2004 by Eli Lilly as an anxiety and depression drug. In 2013, Eli Lilly’s U.S. patent expired and duloxetine became available as a cheaper option.

Duloxetine Uses

Duloxetine is most commonly used to treat major depressive disorder (MDD) and generalized anxiety disorder (GAD). According to the National Institute of Mental Health (NIMH) anxiety disorders affect about 18% of United States adults, which is about 40 million Americans, making it the most common mental illness in the U.S. Meanwhile, major depressive disorder (MDD) affects about 7% of U.S. adults, which is about 16 million Americans, making it the leading cause of disability.

  • Generalized anxiety disorder (GAD): GAD is characterized by excessive worrying, overthinking, indecisiveness, perceiving people and events as threatening, and feeling unable to relax or let thoughts or concerns go. People with GAD might also experience insomnia, fatigue, muscle tension and aches, and stomach aches. People with GAD also often have other forms of anxiety, like panic attacks, obsessive compulsive disorder, and phobias. You can’t think your way out of GAD, but the disorder does respond very well to medication and therapy, particularly cognitive behavioral therapy (CBT).
  • Major depressive disorder (MDD): MDD or clinical depression is not just feeling sad every now and then. When someone has depression, they usually feel persistently sad and lose interest in activities and people they used to enjoy. Depression can make it hard to function normally, like holding a job and maintaining relationships. For some, even things like getting out of bed, showering, or eating can be extremely challenging. Other symptoms of depression include insomnia, fatigue, feeling hopeless or worthless, and frequent thoughts of death and suicide. While depression can’t be cured just by a positive attitude, or thinking your way out of it, it can be greatly helped by therapy and medication.

Duloxetine has also been used to treat chronic pain for those with conditions like arthritis and fibromyalgia, as well as nerve pain (peripheral neuropathy) in those with diabetes.

How Does Duloxetine Work?

Duloxetine is a serotonin-norepinephrine reuptake inhibitor (SNRI). This class of medication works by preventing the reuptake of the neurotransmitters serotonin and norepinephrine by nerve cells, which increases their levels available in the brain. These neurotransmitters are important in the regulation of mood, stress, and pain perception. When levels of available serotonin and norepinephrine in the brain are too low, people can feel depressed, anxious, and more pain from nerves and muscles.

Before You Take Duloxetine

There are some lifestyle behaviors and health conditions that could interfere with the effectiveness or safety of duloxetine. Before beginning treatment, let your doctor know if you take:

  • Stimulants
  • Opioids
  • Herbal remedies
  • Other medications for depression, anxiety, other mental illnesses, Parkinson’s, or migraines

You should talk to your doctor before taking duloxetine if you have or have had:

  • Slow digestion
  • Seizures
  • Kidney or liver disease
  • Bleeding problems
  • Narrow-angle glaucoma
  • Bipolar disorder
  • Manic depression
  • Drug or alcohol addiction
  • Suicidal thoughts or behaviors
  • Pounding heartbeats or heart palpitations

If you are breastfeeding or pregnant, talk to your doctor about the benefits and risks of taking this medication.

Some people, particularly those between the ages of 18-24 years old who have MDD, can have thoughts about suicide when first taking this or other antidepressants. Let your doctor know if your symptoms worsen or if you have suicidal thoughts or behaviors. If you have a child beginning duloxetine, monitor them for any changes in mood or symptoms.

There are some substances and conditions you should avoid when taking duloxetine. Some contraindications are:

  • Duloxetine is not approved for use by anyone younger than seven years old.
  • A dangerous drug interaction can occur between duloxetine and monoamine oxidase inhibitors (MAOIs). To prevent an interaction between drugs, do not use duloxetine within five days before you plan to use an MAOI, or 14 days after you have used an MAOI.
  • Do not take other substances that increase serotonin, such as MDMA (ecstasy), the herb St. John’s wort, other antidepressants in the SSRI or SNRI family, or the supplement tryptophan.
  • Do not drink alcohol or use illegal drugs while you are taking duloxetine, as they may inhibit duloxetine’s effects, increase bad side effects, or put you at risk of liver disease.
  • Avoid driving or operating heavy machinery until you know how duloxetine will affect you. It may cause impaired reactions, dizziness, or fainting, especially in the beginning of treatment before your body is used to the medication.
  • Ask your doctor before using a nonsteroidal anti-inflammatory drug (NSAID) like aspirin (Tylenol), ibuprofen (Advil, Motrin), or naproxen (Aleve).
  • Do not take other drugs for sleep, anxiety, or narcotic pain relief without consulting with your doctor.

Consult with your doctor if you:

  • Are pregnant or breastfeeding
  • Have diabetes
  • Before having surgery, tell your doctor or dentist that you are taking duloxetine

Adults over the age of 65 can be more susceptible to bleeding disorders, dizziness, lightheadedness, coordination issues, or fainting, all of which can increase the risk of falling. Talk to your doctor if you are concerned about the safety of yourself or an older adult taking this medication.

Duloxetine Dosage

Typically, duloxetine is taken once or twice per day. Most doctors will begin patients at a low dose and increase it slowly over a number of weeks until a dose that works for you is reached. Dosages range from 20 mg to 120 mg, with most people taking about 60 mg per day for anxiety and depression. It’s important to take duloxetine exactly as your doctor prescribes it.

The medication can be taken either with or without food, though if you experience nausea as a side effect, taking it with a meal can help. Your doctor will determine what is the best dosage, based mainly on symptoms, age, and the medical condition you’re taking the medication for. The capsule is meant to be swallowed whole, so do not chew, crush, or break it open.

Common dosages for duloxetine treatment, taken once daily or broken into two doses:

  • Major depressive disorder: 30-60 mg daily
  • Generalized anxiety disorder: 30-60 mg daily
  • Peripheral neuropathy in diabetes: 60 mg daily
  • Fibromyalgia: 30-60 mg daily

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How long does it take for duloxetine to take effect?

It’s normal for it to take some time before you feel improvement in your symptoms after beginning duloxetine. The first symptoms to change are often energy, sleep, and appetite, which often improve within 1-2 weeks. Most people notice improvements in their mood and other symptoms by four weeks, though it may take between six and eight weeks for full effects of the medication to be achieved.

What happens if I miss a dose?

If you miss a dose, take it as soon as you remember. However, if it’s almost time for your next dose, just skip the missed dose and take your next one as normal. You should not take both doses at once to make up for the missed one. You can always contact your doctor or pharmacist if you have questions about a missed dose.

Can you stop duloxetine cold turkey? Does duloxetine cause withdrawal symptoms?

It’s important to take this medication as prescribed even if at first you feel side effects or don’t feel any benefits. Stopping taking it suddenly can cause anxiety, fatigue, headache, diarrhea, sleep disturbances, and other side effects. After several weeks, side effects often fade and benefits become more noticeable.

If you want to stop the medication, it’s important to work with your doctor to gradually taper yourself off over at least two weeks. Stopping suddenly or too quickly can cause very uncomfortable withdrawal effects including:

Common Side Effects

The most common side effects of duloxetine are nausea, dizziness, fatigue, dry mouth, insomnia, and gastrointestinal issues like decreased appetite, constipation, or diarrhea. Duloxetine can also increase blood pressure, so your blood pressure will be checked regularly while you’re on this medication. Sexual function can also be affected, like decreased sex drive and delayed orgasm or ejaculation.

While the side effects may seem daunting, most people experience mild side effects, if any at all. Beginning a new medication can be scary, but if your doctor has prescribed duloxetine to you, she or he believes that potential benefits outweigh potential risks. Starting the medication at a very low dose and building up to a therapeutic dose slowly, can help you avoid side effects.

Symptoms organized by body system they affect include:


  • Very common (10% or more): Nausea, constipation, diarrhea, dry mouth
  • Common (1-10%): Abdominal pain, gas, indigestion, vomiting
  • Uncommon (0.1-1%): Difficulty swallowing, gastritis, gastroenteritis, bleeding in the gastrointestinal tract, bad breath
  • Rare (less than 0.1%): Gastric ulcer

Nervous system

  • Very common (10% or more): Dizziness, fatigue, headache
  • Common (1-10%): Distorted sense of taste, pins and needles, decreased sensitivity in skin or in pain perception, tremor
  • Uncommon (0.1-1%): Convulsions, restless leg syndrome, fainting, attentional disturbances in, involuntary muscle movements
  • Rare (less than 0.1%): Akathisia, dysarthria, gait disturbance


  • Very common (10% or more): Insomnia
  • Common (1-10%): Abnormally vivid dreams, agitation, anxiety, panic attacks, sleep disorder
  • Uncommon (0.1-1%): Grinding your teeth, agitation, irritability, impulsivity, and restlessness
  • Rare (less than 0.1%): Aggression and anger, hallucinations, hypomania and mania, suicidal behavior and ideation


  • Common (1% to 10%): Heart palpitations, increased blood pressure, hypertension, hot flashes
  • Uncommon (0.1-1%): Chest pain, heart attack, orthostatic hypotension (especially in the first week of treatment), cold hands and feet, rapid heart beat
  • Rare (less than 0.1%): Severe increase of blood pressure that may increase risk of stroke, abnormal heart rhythms.


  • Common (1-10%): Decreased sex-drive, inability or difficulty achieving orgasm, delayed ejaculation, erectile dysfunction, increased frequency of urination
  • Uncommon (0.1-1%): Painful or difficult urination, abnormal urine odor, menopausal symptoms, increased need to pee at night or day, testicular pain
  • Rare (less than 0.1%): Decreased urine flow, breast discharge, menstrual changes


  • Common (1-10%): Localized or generalized itchiness, excessive sweating
  • Uncommon (0.1-1%): Night sweats, hives, red itchy rash, bruising easily, sensitivity to light
  • Rare (less than 0.1%): Facial swelling, skin discoloration, Stevens-Johnson syndrome


  • Common (1-10%): Musculoskeletal pain, muscle spasms
  • Uncommon (0.1-1%): Muscle stiffness and tightness, muscle twitching


  • Common (1-10%): Blurred vision
  • Uncommon (0.1-1%): Double vision, dry eye, visual impairment
  • Rare (less than 0.1%): Glaucoma


  • Common (1-10%): Cough, sore throat, yawning, upper respiratory tract infection
  • Uncommon (0.1-1%): Laryngitis, a feeling of tightness in the throat
  • Rare (less than 0.1%): Acute bloody nose

Antidepressants like duloxetine can increase your risk of suicidal thoughts and behavior, especially in children and adolescents between the ages of 18-24 who have major depressive disorder.

Lightheadedness and dizziness can occur, especially in the beginning of treatment, and in patients older than 65. To minimize this side effect, stand slowly from a seated or lying position.

Duloxetine Alternatives

Duloxetine belongs to the class of medications called selective serotonin and norepinephrine reuptake inhibitors (SNRIs). These antidepressants are used for treating anxiety, depression, and chronic pain. For some people, a different medication in the same family can be more helpful and cause fewer side effects. If duloxetine doesn’t work for you, you can talk to your doctor about trying another SNRI like:

  • Milnacipran (Savella)
  • Venlafaxine (Effexor)
  • Desvenlafaxine (Pristiq)

Cymbalta vs. Zoloft

If you want to try a different type of medication for anxiety and depression that still works with increasing available serotonin in the brain, you can try a medication that belongs to the family of selective serotonin reuptake inhibitors (SSRIs) such as Zoloft. These medications prevent the reuptake of serotonin after it has been released, increasing available serotonin in the brain. These medications can be very effective for treating anxiety and depression, and they might have fewer side effects than SNRIs, but they don’t treat chronic pain the way SNRIs do. These include:

  • Citalopram (Celexa)
  • Fluoxetine (Prozac)
  • Paroxetine (Paxil)
  • Sertraline (Zoloft)

Is duloxetine a painkiller?

While clinical trials of more than 29,000 people showed that duloxetine significantly reduces chronic pain, it is not exactly understood how duloxetine accomplishes this. One hypothesis is that it blocks sodium from entering cells, which prevents a message of pain from the brain. In addition to duloxetine, those looking to address chronic pain who do not need treatment for anxiety and depression can try:

  • Gabapentin (Gralise)
  • Pregabalin (Lyrica)

If you’d like to try to find a medication that works better for you than duloxetine, visit your doctor to discuss alternatives. You can find a comprehensive list of alternatives to duloxetine, as well as a comparison of their side effects and specific targets of treatment here.

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When to See a Doctor

It’s very rare, but a serious allergic reaction to duloxetine is possible. If you have an allergic reaction while on this medication, get medical attention right away. Symptoms of a serious allergic reaction include:

  • Severe dizziness
  • Hives, or red or purple rash with blistering or peeling
  • Itching or swelling, especially of the mouth, face, or throat
  • Difficulty breathing
  • Seizure

Also make sure to tell your doctor if you notice any of the following, which are signs that the medicine is not working as it should:

  • Worsening mood including depression and anxiety
  • Panic attacks
  • Insomnia
  • Feeling agitated, impulsive, aggressive, restless, or hyperactive
  • Confusion
  • Thoughts of causing harm to yourself or suicide

If you suspect an overdose, seek emergency medical attention (by calling 911), or call the poison help line at 1-800-222-1222. Symptoms of overdose can include:

  • Seizures
  • Fainting
  • Severe drowsiness
  • Rapid heart rate
  • Coma

Very rarely, this medication and other medications that increase serotonin can cause serotonin syndrome. This is a very serious condition that requires immediate medical attention. Seek help if you experience:

  • Hallucinations
  • Uncontrolled muscular twitching
  • Unusual agitation or restlessness
  • Nausea and vomiting or black, bloody stool
  • Fever
  • Rapid heart rate
  • Severe dizziness
  • Loss of coordination

Antidepressants like duloxetine can increase your risk of suicidal thoughts and behavior, especially in children and adolescents with major depressive disorder. If you or your children under 24 years notice mood changes or suicidal ideation, especially in the beginning of treatment, notify your doctor or seek medical attention right away.

How K Health Can Help

Anxiety and depression are among the most under-reported and under-treated diseases in America. Nearly 20% of adults in the US suffer from mental health illness and fewer than half receive treatment. Our mission is to increase access to treatment for those suffering in silence.

You can start controlling your anxiety and depression and get access to the treatment you need with K Health. Starting at $12/month get prescriptions for mental health medications plus unlimited doctor visits through the K Health app. Start your free assessment to see if you’re eligible.

K Health articles are all written and reviewed by MDs, PhDs, NPs, or PharmDs and are for informational purposes only. This information does not constitute and should not be relied on for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment.

Jenell Decker, MD

Dr. Decker is a family medicine physician who completed her residency at East Carolina University School of Medicine. She graduated medical school from Marshall University School of Medicine.

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