Part of my job as a Longevity Medicine specialist is to determine what works and what doesn’t, and right now the spotlight is on IV (intravenous) NAD+. From celebrity endorsements (Hailey Bieber, Kendall Jenner, Gwyneth Paltrow, and Chelsea Handler have all publicly touted its benefits) to biohacker influencers (don’t get me started), it’s a molecule that is having its moment. But NAD+ (Nicotinamide Adenine Dinucleotide), an essential co-enzyme in cell metabolism, is often misunderstood and its function oversimplified. Supporting NAD+ is a good thing, but before you rush out to a wellness clinic for IV infusions, you need to know why NR (Nicotinamide Riboside) is a better alternative.
Role and Importance of NAD+
NAD+ (the plus sign indicates its oxidized form) is a derivative of niacin, and is essential to optimum energy processing in cells. I first began looking into it many years ago when I was researching resveratrol, which helped to reveal how healthy lifespan extension seen with fasting and caloric restriction works. The effect involves activation of anti-aging factors called sirtuins, which in turn need NAD+, which declines with age. Higher NAD+ in cells is associated with slower aging and helps to combat inflammation and oxidative damage. Boosting NAD+ levels to go beyond what can be accomplished with extreme caloric restriction makes sense. There’s very good evidence that this can be easily accomplished by taking supplements in pill form containing a NAD+ precursor molecule called NR (Nicotinamide Riboside). In fact, NAD+ does not normally circulate and is created inside the cell from NR; intravenous NAD+ must be converted back into NR in order to enter cells. So why infuse NAD+ rather than just taking NR, which produces more sustained levels? It doesn’t.
Evidence for IV NAD+
A major problem in Longevity Medicine is the scarcity of clinical studies supporting many of its practices. There are some with very high-level evidence, such as Therapeutic Plasma Exchange (TPE), but many others with hardly any. Intravenous NAD+ is one of these. Until recently, there was only one published clinical study, and it is not especially convincing. [1] This was a pilot study – a preliminary look – and what it found was that for the first few hours of infusion, NAD+ and its metabolites were rapidly and completely cleared. Hardly a ringing endorsement.
Evidence Against IV NAD+
One of the traps in evaluating potential longevity interventions is oversimplification and not considering their possible adverse effects. Most biomolecules have undesired “off-target” interactions, and in the case of NAD+, its side hustle is signaling inflammation. Elevated circulating levels of NAD+ are a marker of cell senescence, and boosting the amount of NAD+ in the circulation may actually drive aging faster.
Introducing Intravenous NR at Phase Plastic Surgery
NAD+ infusions may soon be obsolete anyway. Since it has to be converted into NR before it can enter cells, it would be more efficient to infuse NR, but pharmaceutical-grade NR has not been available in an injectable formulation until recently. In a study released in February 2026 in preprint (not yet peer-reviewed) comparing IV NAD+ to IV NR, the NR group actually had superior NAD+ levels post-treatment, with no adverse effects, while the NAD+ group had elevated white blood cell counts, indicating a state of heightened inflammation. [2]
I find that credibility is increasingly hard-won in Longevity Medicine, and NAD+ infusions are emblematic of the problem. It’s a parallel issue in plastic surgery, where consumer decisions are driven by social media more than credentials and proven expertise, so I shouldn’t be surprised. I don’t begrudge anyone trying to move their medical practice into the 21st century with Longevity Medicine, but if we don’t follow the best evidence, then the true breakthroughs get lost in the hype. I am happy to offer NR infusions at Phase Longevity and just as happy that I didn’t get on the IV NAD+ bandwagon. Contact us today to learn more about why NR is a better alternative to intravenous NAD+.
- Grant R, Berg J, Mestayer R, Braidy N, Bennett J, Broom S, Watson J. A Pilot Study Investigating Changes in the Human Plasma and Urine NAD+ Metabolome During a 6 Hour Intravenous Infusion of NAD. Front Aging Neurosci. 2019 Sep 12;11:257.
- Randomized, placebo-controlled, pilot clinical study evaluating acute Niagen®+ IV and NAD+ IV in healthy adults. Jessie Hawkins, Rebecca Idoine, Jun Kwon, Andrew Shao, Elizabeth Dunne, Elizabeth Hawkins, Kayla Dawson, Yasmeen Nkrumah-Elie
doi: https://doi.org/10.1101/2024.06.06.24308565 (preprint)
