Nicotinamide Riboside (NR)

The bottle promised cellular energy. Eight weeks in, the only thing that has measurably risen is a number in your blood.

That is not a discipline problem. It is an information problem. Nicotinamide riboside is the most-studied NAD+ precursor ever sold. Twenty-five human trials, all agreeing on one result: NR raises blood NAD+, reliably, at every dose tested. What that raised number does to your blood pressure, your blood sugar, your muscles and your brain is a far messier story, and it is the story nobody selling a longevity supplement wants to tell.

Twenty-eight chapters tell it. Trial by trial, dose by dose, with journals and sample sizes attached so you can check every one.

Every claim carries a grade

PROVEN. PROMISING. THEORY. NO DATA. Graded on the evidence alone, including the claims that favor NR. A claim that cannot earn a grade does not make the page.

The one number that changes how you read a label. Safety has been tested to 3,000 mg a day and came back clean. Benefit has never been shown above roughly 1,000 mg. Everything priced above that line is sold on the first curve while implying the second.

The real cardiovascular evidence. The nine-point systolic blood pressure drop that made headlines, and the exploratory subgroup it came from. The peripheral artery disease trial where NR moved real walking distance against placebo. The failing heart study that tested it in the exact tissue the biochemistry points to.

Where the story stops. Two rigorous insulin resistance trials came back negative on blood sugar. The longest cognitive trial here missed every primary outcome. Brain fog, the symptom that sells the most supplements and has no diagnostic code, gets its causes ranked by testability.

The mouse that lived longer. One species, one 2016 paper, and the reason every anti aging supplement page still traces back to it. And why it has never been repeated in a human being.

NR vs NMN, on 2026 data. Two head-to-head trials finally ran the comparison in the same people. They disagree, and why tells you more than either result alone. The whole precursor family, niacin, niacinamide, NMN and the IV drip, ranked once by price and again by evidence. Peptide stacks and the combination math nobody runs.

The half of the research nobody ran. Three of the most-cited NR trials enrolled men only. Most mixed-sex trials never reported results by sex. An entire Part covers women, menopause, and the flat dose sized for a body nobody measured, including the one insulin sensitivity result from a trial built around postmenopausal women.

What to actually buy. Side effect rates against placebo. The dose range where the benefit evidence lives, not the range the label calls safe. Three lines on a supplement label that decide whether a bottle is worth the money, five red flags, how proprietary blends hide a dose, and price per effective dose. Where NAD+ sits in your antioxidant defenses, and what it does and does not do for mitochondria, ATP and brain health.

Then test it on yourself. Two weeks to a baseline. Eight weeks to an answer. Twelve weeks to a decision you can defend, with stop rules and an outcome that carries a number.

Written for anyone watching a systolic number climb, tracking cognitive change in older adults, or already comparing longevity supplements. It will not tell you your stack is wrong. It will tell you which parts carry evidence and which carry hope, and it does the same to NR without flinching. If you want certainty, the marketing is free.

Book Four in The Longevity Molecule series. Evidence first, hype never.

Stop paying for a bigger number in your blood. Get the graded answer, then decide.