Anti-aging supplements are having quite the moment right now, targeting everything from skin and hair to metabolism and brain health. The latest to join the ranks is nicotinamide mononucleotide—or NMN—a slightly tongue-twisting name that’s been popping up everywhere, especially within celebrity circles. These supplements aim to boost levels of a molecule in the body called NAD+, which plays a key role in cellular energy production and metabolic health.
Most notably, Kim Kardashian revealed she’s spent the past year taking NMN supplements, while other well-known celebs—including Kendall Jenner, Hailey Bieber, and Jennifer Aniston—swear by NAD+ infusion therapy. (Bieber, for one, has said she plans to use it “for the rest of her life” to “never age.”)
NMN supplements are also gaining traction on TikTok, with some users claiming it can help you age in reverse—but what does the science say, exactly? While the role of supplements like melatonin or vitamin patches is fairly straightforward, NMN is a bit more…complicated.
Read on to learn how NMN works, what the supplements are supposed to do, and what the research actually shows.
A simple(ish) breakdown of NAD+
NAD+ (nicotinamide adenine dinucleotide) is a crucial helper molecule (or coenzyme) found in all living cells. It plays a fundamental role in turning food into energy, repairing DNA, and supporting overall cellular function.
“NAD+ is essential for the development of healthy cellular replication and nearly every process within the body,” Amanda H. Corbett, PharmD, FCCP, FAIHM, associate professor at UNC Eshelman School of Pharmacy, tells SELF. “Think of it like you need hemoglobin to carry oxygen throughout your body. NAD+ is a similar critical factor within the body.”
Board-certified internist and longevity expert Amanda Kahn, MD, tells SELF that NAD+ is “foundational to longevity biology because it supports how efficiently our cells produce energy and respond to stress.”
NAD+ levels naturally decline with age. While not everyone may notice a difference, Dr. Kahn says this drop can lead to lower energy, slower recovery, and reduced physiological resilience over time.
How the body makes NAD+—and why NMN is getting so much attention
Your body makes and maintains NAD+ in a few natural ways. Vitamin B3 (niacin and nicotinamide), found in foods like poultry, fish, and whole grains, is the primary dietary source. So when NAD+ levels start to drop with age, it seems logical to just boost your B3 intake, right?

