What Is Cymbalta (Duloxetine) Used For?

Cymbalta is the brand name for duloxetine, an SNRI antidepressant approved in the US for depression, generalized anxiety and three kinds of chronic pain.

By withClaro Editorial · 2026-11-02 · 4 min read

Clinical section reviewed by Dr. Jason Tan, Consultant Psychiatrist, on October 27, 2026.

More about Cymbalta

Key takeaways

Cymbalta is the brand name for duloxetine, approved in the US for depression, generalized anxiety, diabetic nerve pain, fibromyalgia and chronic muscle and joint pain.
It is an SNRI: it acts on serotonin and norepinephrine, not on serotonin alone like SSRIs.
The usual dose is 60 mg once a day; some people start at 30 mg for a week to adjust.
The label warns about liver injury with heavy drinking, and stopping it should be gradual.

Cymbalta is used for depression, generalized anxiety and three kinds of chronic pain. Its generic name is duloxetine, and it was first approved in the US in 2004. It is one of the most prescribed antidepressants in the US, filled by about 4.1 million people in ClinCalc's 2024 estimates, and its approval for pain sets it apart from most of them.

What is Cymbalta used for?

The FDA approves Cymbalta for major depressive disorder and generalized anxiety disorder in adults, and for generalized anxiety in children 7 and older. It is also approved for nerve pain from diabetes, fibromyalgia and chronic muscle and joint pain, such as low back pain and osteoarthritis. That pain role sets it apart from most antidepressants.

Is Cymbalta an SSRI?

No. Cymbalta is an SNRI, a serotonin and norepinephrine reuptake inhibitor. SSRIs such as Zoloft and Lexapro act mainly on serotonin, the NHS notes, while SNRIs act on both. Effexor is another SNRI. For the other types, see the list of antidepressants.

How does Cymbalta work?

Medically reviewed by Dr. Jason Tan on October 27, 2026, this section only.

The label says the exact way it works for depression, anxiety and pain is unknown, but it is thought to come from boosting serotonin and norepinephrine activity in the central nervous system. For pain, the label puts it down to central pain inhibition: serotonin and norepinephrine take part in the pathways by which the brain and spinal cord damp down pain signals, which is thought to explain why duloxetine can ease some chronic pain apart from any effect on mood. MedlinePlus says the full benefit can take 1 to 4 weeks or longer. The clinical view:

Antidepressants change how the brain uses chemical messengers, but how this lifts mood is not fully understood.

The chemical change starts within hours, yet the full effect on mood takes weeks. Current thinking points to early changes in how the brain processes emotion, then slower changes in receptors, in brain circuits that handle emotion, and in how the brain forms new connections. ## What doses does Cymbalta come in?

Cymbalta capsules come in 20 mg, 30 mg and 60 mg. They are delayed-release, so they are swallowed whole, not opened or split. Your prescriber sets the dose and any increase; the label's figures are a reference to bring to that conversation.

Condition	Usual dose	Maximum
Depression	40 to 60 mg a day	120 mg
Generalized anxiety	60 mg once a day	120 mg
Nerve pain, fibromyalgia, muscle and joint pain	60 mg once a day	60 mg

Some people start at 30 mg for a week to adjust. The label says it should not be prescribed with substantial alcohol use or chronic liver disease, and to avoid it with severe kidney problems. More in Cymbalta dosage.

How long does Cymbalta stay in your system?

Usually about two to three days after the last dose, by the usual rule that a drug takes about five half-lives to clear. Duloxetine's half-life is about 12 hours, which is also why a missed dose can be felt within a day. Steady levels are reached in about 3 days of regular dosing. Because levels fall quickly, stopping suddenly can bring withdrawal symptoms; the label recommends a gradual reduction. More in Cymbalta withdrawal.

What side effects does Cymbalta cause?

In the trials for depression and anxiety, the most common side effects were nausea, dry mouth, sleepiness, constipation and sweating, and nausea and sleepiness often ease in the first weeks. Weight can change too: a 2024 study of medical records for 183,118 people found that, compared with sertraline at six months, duloxetine meant about 0.34 kg more gain and a 10% to 15% higher risk of gaining at least 5% of body weight.

Is Cymbalta safe with alcohol?

For most people the question is about the liver rather than a single drink. The label says Cymbalta should not be prescribed to people with substantial alcohol use or chronic liver disease, because the two together may cause liver injury. In a label study, Cymbalta did not add to alcohol's effect on thinking and coordination, but how much you drink is something to tell your prescriber honestly. Signs of liver trouble include itching, pain under the right ribs, dark urine, and yellow skin or eyes; any of them needs a call to your prescriber straight away.

Does Cymbalta have a boxed warning?

Yes. Like other US antidepressants, it carries an FDA boxed warning: suicidal thoughts and behavior can rise in children, teenagers and young adults aged 24 and younger. The risk is highest in the first months and after a dose change, and the label asks families and caregivers to watch too, for new anxiety, agitation, panic, poor sleep or sudden changes in mood or behavior. If you're having thoughts of harming yourself, contact emergency services or a crisis line straight away. In the US, call or text 988. In the UK, call Samaritans on 116 123. Elsewhere, find a crisis line near you.

What should you tell your prescriber before starting Cymbalta?

Some conditions and medications change whether Cymbalta is a good fit, so name them at the first appointment. Before you start, tell your prescriber about:

any liver or kidney problems
how much alcohol you drink
other antidepressants, migraine medicines, blood thinners or pain relievers
high blood pressure, glaucoma or a history of mania, each of which the label warns about
pregnancy, plans for pregnancy or breastfeeding

Download on the App Store Cymbalta can change pain, sleep and mood on different timelines. The withClaro app lets you log mood, sleep, energy and side effects each day, linked to your dose, and turns it into a report for your prescriber.

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Sources

Claro articles are for self-monitoring and educational purposes only. They are not a medical device, therapist, or diagnostic tool, and do not replace care from your prescribing clinician. If you are in crisis, contact your care team, emergency services, the Samaritans (UK: 116 123), or the Crisis Text Line (US: text HOME to 741741).

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