To put it lightly, the supplement world is confusing. Take a walk down the vitamin aisle at the store, and you'll find endless letters, numbers, and symbols plastered on the bottles without much description, leaving you googling acronyms like BCAAs and CBD. Another mysterious letter combo is rising in popularity: NAD+.

NAD+ supplements jumped to the top of feeds after HaiIey Bieber and Kendall Jenner praised its benefits while getting a NAD-inflused IV drip on an episode of The Kardashians. “I’m going to NAD for the rest of my life and I’m never going to age,” Bieber said.

Are the supermodels onto something? Dietitians explain.