By Naomi Carr

Last updated: 09 February 2024 & medically reviewed by Morgan Blair

Cymbalta is the brand name for an antidepressant medication containing duloxetine. It is used to treat several mental and physical health conditions. Cymbalta may cause several side effects, including nausea, dizziness, dry mouth, fatigue, and decreased appetite. It can also cause serious side effects, that in some cases require a change of medication or professional treatment.[1]

What is Cymbalta?

Cymbalta is a brand-name medication containing duloxetine. It is in the class of antidepressants called serotonin and norepinephrine reuptake inhibitors (SNRIs) and is prescribed to treat several physical and mental health conditions. Cymbalta is available as a delayed-release capsule in 20 mg, 30 mg, and 60 mg strengths. [2]

What is Cymbalta used for?

Cymbalta is approved to treat various conditions, including: [1]

  • Fibromyalgia

  • Diabetic peripheral neuropathic pain

  • Chronic musculoskeletal pain

It is also sometimes used off-label to treat other mood and anxiety disorders, pain conditions, and urinary incontinence. [3]

A typical dose of Cymbalta is 30-120 mg per day. Individuals are gradually tapered onto the medication to find a therapeutic dose and reduce the risk of side effects. [1]

Why do people abuse Cymbalta?

SNRIs, such as Cymbalta, are not a commonly abused class of medications, as they generally do not cause a feeling of euphoria or ‘high’ and are not habit-forming. However, some people have been found to misuse or abuse Cymbalta, by taking larger doses than prescribed or by taking it alongside other substances to enhance or alter the effects. [1][4]

Although Cymbalta is not considered an addictive substance, it is possible to develop a physical dependence on the medication. This can result in Cymbalta withdrawal symptoms when the medication is stopped and may contribute to misuse or abuse. [3][4]

Common side effects of Cymbalta

When commencing Cymbalta treatment or changing the dosage, it is common to experience side effects. Often, these side effects last a short time and are alleviated within two weeks. Common side effects of Cymbalta include: [1][2][5]

  • Dry mouth

  • Nausea

  • Vomiting

  • Constipation

  • Diarrhea

  • Weakness

  • Tiredness

  • Fatigue

  • Decreased appetite

  • Increased sweating

  • Anxiety

  • Insomnia

  • Irritability

  • Impulsivity

  • Blurred vision

  • Shaking

  • Decreased libido

  • Sexual dysfunction

  • Vivid or unusual dreams

Severe side effects of Cymbalta

Some people may experience severe side effects when taking Cymbalta. If any of the following side effects occur, it is important to consult with a doctor, as a change of medication or dosage may be required: [1][2][5]

  • Severe stomach pain or swelling

  • Yellowing of the skin or eyes

  • Unusual bleeding or bruising

  • Extreme fatigue

  • Fainting or falling

  • Persistent vomiting or diarrhea

  • Fever

  • Rash, hives, or blisters

  • Swelling of the face or throat

  • Trouble breathing

  • Seizures

  • Mania: Cymbalta can increase the risk of a manic episode, particularly in individuals with a history of mania or bipolar disorder.

  • Serotonin syndrome: Use of Cymbalta alone or combined with other serotonergic medications can increase the risk of serotonin syndrome, which includes symptoms such as fever, confusion, and extreme fatigue.

Suicidal ideation

It is important when taking Cymbalta to be aware of the risk of new or worsening suicidal ideation, particularly in those under the age of 24. Antidepressants can be used to treat the symptoms of depression, including suicidal thoughts, although they may cause a temporary worsening in these symptoms when commencing a new treatment. [1]

Individuals taking Cymbalta and their family members should look for any concerning changes in mood or behavior and any emerging thoughts or attempts of suicide. The prescribing doctor will also monitor throughout treatment for these symptoms and provide necessary treatment or support. [5]

Discontinuation syndrome

Although Cymbalta is unlikely to cause the development of an addiction, it can cause some physical dependence. This can lead to the onset of withdrawal symptoms, or discontinuation syndrome, when the medication is stopped, particularly if it is stopped abruptly and after prolonged use. [3]

This can include symptoms such as nausea, vomiting, dizziness, headache, fatigue, insomnia, anxiety, sensory disturbances, and seizures. It is recommended to gradually taper off the medication when discontinuing Cymbalta treatment, to help prevent or reduce this risk. [1]

Cymbalta overdose

Cymbalta can cause a severe or fatal overdose if taken in large doses or when combined with additional substances, such as alcohol. Individuals taking Cymbalta may be at risk of accidental or intentional overdose. Signs of a Cymbalta overdose can include: [1][2]

  • Rapid or irregular heart rate

  • Vomiting

  • Fever

  • Hallucinations

  • Mania

  • Extreme fatigue

  • Agitation

  • Seizure

  • Loss of consciousness

In the event of a Cymbalta overdose, call 911 immediately.

Getting treatment for Cymbalta dependence

Antidepressants, such as Cymbalta, are not typically associated with addiction or dangerous withdrawal. As such, individuals taking Cymbalta do not tend to require specialized services to assist with detox or withdrawal. However, some people may use Cymbalta alongside other substances or in the context of a substance use disorder and may require professional intervention to reduce substance use and addictive behaviors. [4]

Individuals taking Cymbalta as prescribed will generally be monitored and reviewed by the prescribing clinician throughout treatment. If it is deemed necessary to discontinue Cymbalta treatment, the doctor will advise on safe cessation. Typically cessation will involve a gradual dose reduction over several weeks to help prevent withdrawal symptoms if physical dependence has developed. [1]

Stopping or changing mental health medication can result in new or worsening symptoms. As such, individuals should continue to receive appropriate professional support to manage their symptoms. This can include therapeutic interventions such as cognitive behavioral therapy, family therapy, support groups, or interpersonal therapy. [3][6]