NAD+ Supplements: Does NMN or NR Actually Work for Longevity?

NAD+ is the molecule at the center of the longevity supplement conversation. David Sinclair takes it. Bryan Johnson takes it. The research on NAD+ and aging is genuinely interesting. But the translation from rodent studies to human benefits is where things get complicated.

Here’s the honest breakdown.

What NAD+ Is and Why It Declines

NAD+ (nicotinamide adenine dinucleotide) is a coenzyme found in every cell of your body, essential for over 500 enzymatic reactions — including energy production, DNA repair, and the activation of sirtuins (proteins associated with longevity). NAD+ levels decline approximately 50% between the ages of 40 and 60 in humans. This decline correlates with — though hasn’t been proven to cause — many hallmarks of aging.

NMN vs NR — What’s the Difference

Both NMN (nicotinamide mononucleotide) and NR (nicotinamide riboside) are NAD+ precursors — meaning your body converts them into NAD+. NR has a longer research history and more published human trials. NMN has become more popular recently, partly through David Sinclair’s advocacy, and newer research suggests it may be converted to NAD+ more efficiently in some tissues.

The honest answer: the clinical difference between NMN and NR in humans is not yet clearly established. Both raise NAD+ levels. Whether that translates to meaningful longevity benefits in healthy humans is still being studied.

What the Human Research Shows

Human trials on NR supplementation show consistent NAD+ level increases in blood — typically 40-90% above baseline. What those increased levels produce in terms of measurable health outcomes is less clear. Some trials show improvements in muscle function and fatigue in older adults. Others show modest improvements in metabolic markers.

The 2023 NONAME trial — one of the most rigorous NMN human studies to date — found that 300mg NMN daily improved muscle insulin sensitivity and physical performance in older men. Encouraging but not conclusive for broader longevity claims.

The Honest Assessment

NAD+ precursor supplements are probably beneficial for people over 40 whose NAD+ levels have declined meaningfully. For people under 35 with good sleep, regular exercise, and adequate nutrition, the NAD+ elevation from supplements may produce minimal additional benefit — because their baseline NAD+ is already reasonably high.

The most cost-effective ways to maintain NAD+ that don’t require supplementation: regular aerobic exercise (consistently shown to raise NAD+ levels), cold exposure, fasting, and adequate sleep.

My Picks If You Want to Supplement

Tru Niagen (NR, 300mg) — ~$40/month — The most studied NR product with the most published research behind it. Backed by ChromaDex, the company that holds multiple NR patents. Tru Niagen Official Site →

Momentous NMN (500mg) — ~$60/month — Third-party tested, clean formula, reputable manufacturer. If you’re choosing NMN over NR, this is the product I’d trust. Momentous Official Site →

Start with one month of either to assess subjective energy and recovery changes. NAD+ supplementation is one of the more evidence-adjacent longevity interventions — not proven, not hype, genuinely interesting and worth monitoring as research continues.