Cymbalta is a brand name for duloxetine, an antidepressant developed by Eli Lilly and Company. Approved by the FDA, Cymbalta is used to treat major depressive disorder, generalized anxiety disorder, and certain types of chronic pain, such as diabetic neuropathic pain and fibromyalgia. It belongs to the class of medications known as serotonin-norepinephrine reuptake inhibitors (SNRIs), which work by increasing levels of serotonin and norepinephrine in the brain to help improve mood and alleviate pain. Common side effects include nausea, dry mouth, and dizziness. Cymbalta is typically taken orally in capsule form, usually once or twice daily.