Marketers say NAD+ pills and infusions can boost longevity. What's the evidence?

Sunnu Rebecca Choi for NPR Scientists carrying out research on the compound nicotinamide adenine dinucleotide — or simply NAD+ — are running into an unusual problem these days: A little too much publicity around their subject of study. Enthusiasm for NAD+ boosting supplements, injectables and IV infusions has overtaken the wellness and longevity world, attracting A-list celebrities and biohackers — and sparking all manner of claims about its ability to boost energy, combat aging and enhance …