Took my 3 capsules at 8 PM yesterday. Maybe I should have waited to start in the morning as I had trouble getting to sleep. Not from any particular symptom, just didn't get drowsy as I usually do. But it had been a challenging day dealing with my husband's progressively worsening younger onset Alzheimer's. During the day today I felt reasonably fine, but I really wanted to nap in the early afternoon. Resisted and hoping now after dose #2 sleep will come normally. So far I would say Imbruvica is a piece of cake. Sweet dreams all.