Medication Guide
Cymbalta (Duloxetine): Uses, Side Effects & What to Expect
Duloxetine — sold as Cymbalta — is an SNRI that raises both serotonin and norepinephrine. It treats depression and generalized anxiety, and uniquely also several chronic pain conditions (diabetic nerve pain, fibromyalgia, ongoing musculoskeletal pain). Early effects appear in 1–2 weeks; the full mood benefit usually takes 4–6 weeks. It should be tapered, not stopped suddenly.
Clinically reviewed by the Lyte Psychiatry Clinical Team · Last reviewed June 2026
What is duloxetine?
Duloxetine is a serotonin-norepinephrine reuptake inhibitor (SNRI). Unlike SSRIs, which mainly raise serotonin, it raises two messengers — serotonin and norepinephrine — which is part of why it helps both mood and certain kinds of pain. It’s sold as Cymbalta and as a generic.
What does Cymbalta treat?
Duloxetine is FDA-approved for major depressive disorder, generalized anxiety disorder, diabetic peripheral neuropathic pain, fibromyalgia, and chronic musculoskeletal pain. That dual mood-and-pain benefit is often why it’s chosen.
How long does it take to work?
Some early effects can appear within the first one to two weeks, while the fuller benefit for mood usually develops over four to six weeks. Pain benefits can also build gradually.
Common side effects
Most side effects are mild and ease over time. The most common include:
- Nausea
- Dry mouth
- Feeling sleepy or tired
- Constipation or reduced appetite
- Increased sweating
- Dizziness
It can also raise blood pressure in some people, so your prescriber may check it.
A note on dosing
Dosing is individualized by your prescriber based on your diagnosis, other medications, and response. This page intentionally doesn’t give a specific number — the goal is the lowest effective dose, adjusted with your clinician.
An important safety note
Like all antidepressants, duloxetine carries an FDA “boxed warning”: in people under 25, antidepressants can in rare cases increase suicidal thoughts, especially early in treatment. Close early follow-up is how we manage this. Because duloxetine can affect the liver, it’s usually avoided with heavy alcohol use. If you or someone you love has thoughts of self-harm, call or text 988 (the Suicide & Crisis Lifeline) right away.
Stopping duloxetine safely
Duloxetine should be tapered, not stopped abruptly. Stopping suddenly can cause discontinuation symptoms like dizziness, nausea, irritability, and flu-like feelings — about one in six people who stop abruptly notice them. A gradual, planned step-down with your prescriber greatly reduces this.
Frequently asked questions
What is Cymbalta (duloxetine) used for?
Duloxetine (brand name Cymbalta) is an SNRI antidepressant FDA-approved for major depressive disorder, generalized anxiety disorder, diabetic nerve pain, fibromyalgia, and chronic musculoskeletal pain.
How long does Cymbalta take to work?
Early effects can appear within 1 to 2 weeks, while the full benefit for mood usually takes 4 to 6 weeks. Pain relief may also build gradually.
What are the common side effects of duloxetine?
Common side effects include nausea, dry mouth, sleepiness, constipation, reduced appetite, increased sweating, and dizziness. It can also raise blood pressure in some people.
Is Cymbalta addictive?
No. Duloxetine is not a controlled substance and is not addictive. However, it should be tapered rather than stopped suddenly to avoid discontinuation symptoms.
How do I stop taking Cymbalta safely?
Always taper with your prescriber. Stopping abruptly can cause dizziness, nausea, irritability, and flu-like feelings. A gradual step-down plan greatly reduces this risk.
Can Cymbalta help with pain?
Yes. In addition to depression and anxiety, duloxetine is FDA-approved for diabetic nerve pain, fibromyalgia, and chronic musculoskeletal pain, which is often why it is chosen.
Related pages
This page is for general education and is not medical advice or a substitute for care from your own clinician. Medication decisions should always be made with a licensed prescriber who knows your history.
Wondering if Cymbalta is right for you?
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