There was an interesting report in Science today. They showed that when the circadian clock was experimentally disrupted, NAD+ supplements could restore function to the mitochondrion. Press release NAD+ supplements used to make me feel 100% normal for a day and then result in a severe crash. The reduced form (NADH) from Prohealth.com has been pretty effective for me when taken on an empty stomach. There's a new form of vitamin B3 that is supposed to be an effective precursor to NAD+. I've never tried it so I can't report on its effectiveness. It's called nicotinamide riboside.