Duloxetine is used to treat depression in adults and generalized anxiety disorder (GAD; excessive worry and tension that disrupts daily life and lasts for 6 months or longer) in adults and children 7 years of age and older. Duloxetine is also used to treat pain and tingling caused by diabetic neuropathy (damage to nerves that can develop in people who have diabetes) in adults and fibromyalgia (a long-lasting condition that may cause pain, muscle stiffness and tenderness, tiredness, and difficulty falling asleep or staying asleep) in adults and children 13 years of age and older. It is also used to treat ongoing bone or muscle pain such as lower back pain or osteoarthritis (joint pain or stiffness that may worsen over time) in adults. Duloxetine is in a class of medications called selective serotonin and norepinephrine reuptake inhibitors (SNRIs). It works by increasing the amounts of serotonin and norepinephrine, natural substances in the brain that help maintain mental balance and stop the movement of pain signals in the brain.