Info Cart -

Duloxetine (Cymbalta®)

Summary: Duloxetine (Cymbalta®) belongs to a group of medications called antidepressants. Duloxetine may be used to treat several conditions.
Add to Info Cart

What is duloxetine used for?

Duloxetine is used as part of the treatment of:

  • Depression
  • Depression associated with body pain
  • Generalized anxiety disorder
  • Anxiety disorders such as panic disorder, separation anxiety disorder, obsessive-compulsive disorder (OCD) and posttraumatic stress disorder (PTSD)

Your doctor may be using this medication for another reason. If you are unclear why this medication is being prescribed, please ask your doctor.

How does duloxetine work?

Duloxetine is a “Serotonin and Norepinephrine Reuptake Inhibitor” (SNRI). This means it increases the amount of certain chemicals in the brain called serotonin and norepinephrine. It is believed that these brain chemicals are not working well in people with problems such as depression or anxiety. It may also slightly increase another chemical in the brain called dopamine.

Duloxetine in children and adolescents

Duloxetine is commonly used in adults. In children and adolescents however, like many medications used to treat childhood disorders, duloxetine has not been officially approved by Health Canada for use in children and adolescents. Nonetheless, physicians may still often prescribe it "off-label" when it is felt that the potential benefits (e.g., reducing your symptoms) of using duloxetine outweigh the potential risks (e.g., the side effects).

How should duloxetine be taken?

Duloxetine is usually taken once or twice a day with or without food (food may help reduce early symptoms of nausea). This medication should be taken at the same time(s) each day as directed by your doctor. Try to connect it with something you do each day (like eating breakfast or brushing your teeth) so that you don’t forget. Try to avoid alcohol when taking duloxetine.


Swallow delayed release duloxetine capsules whole with fluid. The capsules and their contents should NOT be opened, chewed or crushed, nor should the contents be sprinkled on food or mixed with liquids.


Usually, your doctor will start with a low dose of duloxetine. This dose will be slowly increased based on how you respond to it. You and your doctor can then discuss the best dosage to stay on based on how you tolerate this medication (how well the medication is working and how you are doing with the side effects of the medication) and how well it helps to decrease your symptoms.

When will duloxetine start working?

Duloxetine must be taken for 3 to 6 weeks before you begin to feel better. Different symptoms may start to improve at different times. For example, improvements in sleep, appetite and energy may be seen within the first 2 weeks. Sometimes, others will notice improvements in you before you do. Full beneficial effects may take 4 to 8 weeks (or longer). Since this medication takes time to work, do not increase, decrease or stop taking it without discussing with your doctor first.


If you are not feeling better within 6 to 8 weeks, your doctor may recommend you take a different medication. There is a small chance that depression or anxiety symptoms may worsen or that you may experience increased thoughts of self harm during the first months of taking this medication (see section on side effects). If this happens, tell your doctor IMMEDIATELY.

How long do I have to take duloxetine?

This depends on the symptoms you have, how frequently they occur and how long you have had them. Most people need to take this medication for at least 6 months. This allows time for your symptoms to stabilize and for you to regain functioning. After this time, you and your doctor should discuss the benefits and risks of continuing treatment.


If you have had several episodes of severe depression and you tolerate this medication well, you may be asked to take this medication for an indefinite amount of time. By continuing to take this medication, you significantly decrease the chance that you may have another episode of depression.  Do NOT stop taking this medication (even if you are feeling better) without discussing it with your doctor first. If you stop taking this medication suddenly, it is possible that your symptoms may return or you may have a bad reaction.


Once you have started taking this medication, you and your doctor will need to monitor for both the beneficial and unwanted effects. Your doctor will likely check your progress and discuss changes in symptoms during the next 3 months to confirm that this medication is working properly and that possible side effects are avoided. At this time, you can discuss how long you might need to take this medication.

Is duloxetine addictive?

No, duloxetine is not addictive. You will not have “cravings” for it like some people do with nicotine or street drugs. If you and your doctor decide it is best for you to stop using duloxetine, your doctor will explain how to safely lower the dose so you won’t feel any unpleasant “flu-like” effects (chills, nausea, vomiting, dizziness, tingling in hands and feet, muscle aches, fever and electrical sensations) as your body adjusts to being without it.

What are the side effects of duloxetine and what should I do if I get them?

As with most medications, side effects may occur when taking duloxetine. Most side effects are mild and temporary. Side effects may occur before any of the beneficial effects. It is possible for some individuals to experience side effects that they feel are serious or long lasting. If this occurs, speak to your doctor about ways to manage them. On the next page are some of the common side effects and potentially serious side effects of taking this medication. In brackets are suggested ways to lessen these effects.


Common side effects


Side effects may be more common when starting a medication or after a dose increase. If any of these side effects is too troublesome for you, please discuss them with your doctor, nurse or pharmacist.

  • Constipation (increase exercise, fluids, vegetables, fruits and fiber intake)
  • Decreased appetite (try eating smaller, more frequent meals)
  • Drowsiness (take the dose at bedtime; this usually lessens over time)
  • Difficulty sleeping (try taking the medication earlier in the day)
  • Dizziness (try getting up slowly from a sitting or lying down position)
  • Dry mouth (try chewing sugarless gum, sour candies, ice chips, or popsicles)
  • Energized/agitated feelings (avoid caffeine from energy drinks, colas and coffee)
  • Excessive sweating (strong antiperspirants can help; talk with your doctor or pharmacist)
  • Headache (try using a pain reliever like acetaminophen (plain Tylenol®))
  • Changes in sexual performance or interest (discuss with your doctor)
  • Stomach aches or nausea (try taking the duloxetine dose with food)
  • Unusually vivid dreams

Uncommon side effects (e.g., those that occur in less than 5% of patients)


Contact your doctor IMMEDIATELY if you have any of these side effects:

  • Change in mood to an unusual state of excitement, irritability or happiness
  • Muscle twitches or stiffness
  • Seizures (also called fits or convulsions)
  • Skin rash, itchy skin or hives
  • Thoughts of self harm, hostility or suicide
  • Uncomfortable sense of inner restlessness or agitation
  • Unusual bruising or bleeding

What precautions should my doctor and I be aware of when taking duloxetine?


Tell your doctor or pharmacist if you:

  • begin taking any other new medication (prescription or non-prescription), since several other medications
  • can interact with duloxetine
  • feel drowsy, dizzy or slowed down. Duloxetine can make some individuals experience these temporary side effects. Duloxetine may increase the effects of alcohol, resulting in more sedation or dizziness. if you feel this way, it is important to avoid operating heavy machinery or driving a car.
  • have a history of diabetes, heart disease, thyroid disease, kidney or liver disease or seizures
  • have any allergies or have experienced a reaction to a medication
  • have any changes in mood or thoughts of self harm
  • if you develop any new medical problem while you are taking an SSRI
  • miss a period, become pregnant or are trying to become pregnant or are breast-feeding

What special instructions should I follow while using duloxetine?

  • Keep all appointments with your doctor and the laboratory.
  • Do not allow anyone else to use your medication.
  • It is a good idea to have a visit or telephone call with your doctor within 1-2 weeks after you start taking duloxetine, and then periodically after that to see how well the medication is working, how well you are tolerating the medication, and to discuss any problems you may have.

What should I do if I forget to take a dose of duloxetine?


If you miss a dose of this medication, take it as soon as possible. However, if it is almost time for your next dose (e.g., within 4 hours), do not take the missed dose or double your next dose. Instead, continue with your regular dosing schedule.


What storage conditions are needed for duloxetine?

  • Keep this medication in the original container, stored at room temperature away from moisture and heat (e.g., not in the bathroom or kitchen).
  • Keep this medication out of reach and sight of children.

Share this information 

You may wish to share this information with your family members to help them to understand your treatment options. Since every person's needs are different, it is important that you follow the advice provided to you by your own doctor, nurse and/or pharmacist and speak to them if you have any questions about this medication.

About this document

Special thanks to the Kelty Centre for Mental Health for permission to adapt this document. The original document was developed by health professionals of BC Mental Health and Addiction Services, and reviewed by the staff of the Kelty Mental Health Centre. French translation provided courtesy of the Ontario Centre of Excellence for Child and Youth Mental Health.

Creative Commons license

You are free to copy and distribute this material unchanged and in its entirety as long as 1) this material is not used in any way that suggests we endorse you or your use of the material, 2) this material is not used for commercial purposes (non-commercial), 3) this material is not altered in any way (no derivative works). View full license at For any other uses, please contact the original rights holder, the Kelty Mental Health Centre.


Information in this pamphlet is offered ‘as is' and is meant only to provide general information that supplements, but does not replace the information from your health provider. Always contact a qualified health professional for further information in your specific situation or circumstance.

Date Posted: Jun 16, 2013
Date of Last Revision: Oct 8, 2016

Was the information on this page helpful?