What is NAD+? Here’s how it works in your body, why it matters, and if supplementation is worth the hype.

It's more than likely that the NAD+ supplement craze has already crossed your path. The Biebers have infused it. Joe Rogan has podcasted about it. Gwyneth Paltrow swears by it and, of course, sells her own Youth-Boost NAD+ Peptide Rich Cream. NAD+ is the latest biohacker's darling. It's in longevity clinics and the wellness aisle, in your dietary supplements and your topical skin care.

NAD+ (short for nicotinamide adenine dinucleotide) is a coenzyme that your body makes naturally—it contributes to energy production and immune function, among other things. But the current obsession with supplementing NAD+ isn’t just about anti-aging. It reflects a broader shift in how people think about healthy aging and extending their healthspan overall. Instead of reacting to symptoms after they emerge, more people are trying to prevent the diagnosis from happening in the first place.

Some studies suggest that many of the ...