Milnacipran is primarily used in the treatment of fibromyalgia, a chronic condition characterized by widespread pain, fatigue, and cognitive disturbances. It helps alleviate pain and improve physical function by increasing the levels of serotonin and norepinephrine in the brain, which are neurotransmitters involved in pain regulation and mood stabilization. Additionally, it is sometimes prescribed for major depressive disorder (MDD) due to its dual-action mechanism, which enhances its antidepressant effects. Patients often experience reduced pain sensitivity and improved emotional well-being with its use. It is typically administered orally and requires careful dosage adjustments based on individual response and tolerance.