Cymbalta contains the active substance duloxetine. Cymbalta increases the levels of serotonin and noradrenaline in the nervous system. Cymbalta is used in adults to treat: •depression. •generalised anxiety disorder (chronic feeling of anxiety or nervousness). •diabetic neuropathic pain (often described as burning, stabbing, stinging, shooting or aching or like an electric shock. There may be loss of feeling in the affected area, or sensations such as touch, heat, cold or pressure may cause pain). Cymbalta starts to work in most people with depression or anxiety within two weeks of starting treatment, but it may take 2-4 weeks before you feel better. Tell your doctor if you do not start to feel better after this time. Your doctor may continue to give you Cymbalta when you are feeling better to prevent your depression or anxiety from returning. In people with diabetic neuropathic pain it can take some weeks before you feel better. Talk to your doctor if you do not feel better after 2 months.