I had the same experience, and so did two other people I know. For a few days (3 or 4) I felt great with only a few hours of sleep, and then I started to feel unwell and confused. My friend became irritable and emotional. I had to cut way down on the turmeric dosage. It must work as a stimulant, maybe. I started going up on the dosage again, and then when it started to keep me up at night (or wake me up at odd hours) I would take a break from it. Experiment to see how much you can take without losing sleep. Believe me, it will catch up with you.
