Cymbalta (duloxetine) typically begins to show noticeable improvement within 2 to 4 weeks after starting treatment, with many people needing about 4 to 6 weeks to feel the full effect for mood-related symptoms. For some symptoms such as sleep, energy, or appetite, you might notice earlier changes (often within the first 1 to 2 weeks), but mood and interest in activities may take longer. Maximum benefit is often reached around 6 to 8 weeks for many patients, though this can vary depending on the individual, the condition being treated (depression vs. anxiety vs. neuropathic pain), and the dosage. If you don’t notice any improvement after about 6 to 8 weeks, or if you experience worsening symptoms, it's important to contact your healthcare provider to assess whether a dose adjustment, a switch to another medication, or additional therapies are appropriate. Common early side effects (which often improve within a couple of weeks) can include nausea, dry mouth, sleep disturbances, and decreased appetite. More persistent or severe side effects—such as significant blood pressure changes, serotonin syndrome symptoms, or sexual side effects—should be discussed with a clinician promptly. If there are any thoughts of self-harm or new worsening mood, seek urgent medical attention.