Duloxetine HCL is a medication used to treat several conditions, including depression, anxiety, and pain caused by nerve damage associated with diabetes (diabetic peripheral neuropathy), fibromyalgia, and chronic pain related to muscles and bones. Duloxetine belongs to a group of medicines known as selective serotonin and norepinephrine reuptake inhibitors (SSNRIs), which work by increasing the activity of chemicals called serotonin and norepinephrine in the brain. Duloxetine is also sometimes used to treat stress urinary incontinence in women. It is available only with a doctors prescription and comes as a delayed-release capsule to take by mouth. If you have diabetes, duloxetine may affect your blood sugar, so it is important to check your blood sugar regularly as directed and share the results with your doctor. Before taking duloxetine, it is important to inform your doctor about all the other medicines you are using, as some medications can interact with duloxetine and cause serious conditions such as serotonin syndrome or neuroleptic malignant syndrome (NMS)-like reactions.