Coenzyme

NAD+ (nicotinamide adenine dinucleotide) is a coenzyme in every cell. It carries electrons in energy metabolism and is used up by sirtuins, PARPs and CD38. Clinics sell it as an intravenous drip, but no trial has tested NAD+ infusions for any health outcome. In a small study, infused NAD+ disappeared from the blood for the first 2 hours. Most human data come from its oral precursors NR and NMN. They reliably raise NAD+, but their effects on health outcomes are mixed and often null.