Not being able to sleep (also called insomnia) is one of the most common side effects reported by people taking Cymbalta. In some people, this side effect improves after a couple of weeks of taking Cymbalta, but difficulty falling asleep or staying asleep can persist in others. Here are some ways you can improve sleep while taking Cymbalta:

• Take your dose of Cymbalta in the morning. Cymbalta may be given once a day or twice a day but for those people experiencing insomnia, it should be taken just once a day in the morning
• Swallow Cymbalta capsules whole; do not crush, chew, or open up the capsules and sprinkle them on food because this may cause Cymbalta to be absorbed more quickly than intended, increasing the risk of side effects such as insomnia
• Do not drink alcohol while you are taking Cymbalta
• If you miss a dose of Cymbalta, never take 2 tablets at once to make up for the missed dose because the drug has a long half-life and side effects are more likely at high plasma levels
• Do not stop Cymbalta suddenly. If you want to stop taking Cymbalta, talk with your doctor who will help you to lower the dose slowly. If Cymbalta is stopped too quickly it can cause a discontinuation (or withdrawal) syndrome, and symptoms include insomnia, irritability, nausea, dizziness, vomiting, nightmares, headache, and paresthesia (a burning or prickling sensation in the hands and feet)
• Talk to your doctor or pharmacist before you take any other medications that can interact with Cymbalta. Some other medications also release serotonin (as does Cymbalta) and too much serotonin can cause a condition called serotonin syndrome, which can be life-threatening and also impact sleep. Examples of medicines that also release serotonin include opioids, lithium, and tramadol
• Try to keep strict sleep hygiene practices; for example, keep to a fixed sleep and wake up schedule, remain active during the day, avoid daytime naps, limit or stop caffeine, nicotine, and alcohol intake, and avoid large meals or beverages close to bedtime
• Cognitive behavior therapy strategies such as stimulus control therapy, relaxation techniques like deep breathing, therapeutic sleep restriction, and light therapy, may also help with sleep

Always let your doctor know if you find it difficult to sleep while taking Cymbalta. Sleep disturbances can also occur if Cymbalta is stopped too quickly, even if it is tapered down slowly; as well as if you take too much Cymbalta or take Cymbalta with interacting medications.