Nicotinamide riboside
NR, Niagen, Tru Niagen
The NAD precursor that stayed legal, has the most human trials in the category, and keeps raising NAD without clearly improving anything measurable.
Human trials
Holds GRAS status and New Dietary Ingredient notifications in the United States, so it is lawfully sold as a supplement. Not an approved drug. Its regulatory position is the mirror image of NMN's.
What it is
Nicotinamide riboside is a form of vitamin B3 that enters the NAD salvage pathway one step further out than NMN. Both raise NAD. The commercial argument between them has been fierce and the evidence separating them is thin.
NR's distinguishing feature is regulatory rather than biochemical: it secured GRAS status and dietary ingredient notifications early, so it has been continuously and lawfully sold while NMN was banned, unbanned and litigated over.
What the trials show
NR has more completed randomised human trials than anything else in this category, which is the strongest thing that can be said for it.
They consistently show that oral NR raises blood NAD in a dose-dependent way and is well tolerated over months. Beyond that the record is mixed to disappointing. Trials in cardiovascular function, insulin sensitivity, muscle performance, Parkinson's disease and cognitive impairment have produced small, inconsistent, or null results. A recent phase 2 randomised pilot in older adults with amnestic mild cognitive impairment adds to a pattern of studies that establish the biomarker moves and struggle to show that anything else does.
That pattern is the honest summary of the whole NAD precursor category. The pharmacokinetics work. The clinical benefit has not been demonstrated.
Practical notes
- The NR versus NMN argument is largely commercial. Both raise NAD. No adequately powered head to head trial has shown either is superior in humans, and the loudest claims come from parties with a stake in one of them.
- Well tolerated is a real finding. Against most of this site, a compound with multiple randomised trials showing good tolerability over months is a relatively comfortable position, even without efficacy.
- Judge it as a supplement, not a therapy. It raises a biomarker safely at a meaningful price. Whether that is worth buying is a different question from whether it is safe.
Side effects and warning signs
Commonly reported
- Generally well tolerated, with adverse events close to placebo across trials
- Nausea and gastrointestinal discomfort at higher doses
- Fatigue, reported inconsistently
Stop and get medical help
- Any active malignancy, on the same unresolved reasoning that applies to every NAD precursor
- Persistent symptoms attributed to the supplement, since the safety data covers months rather than years
Sources
From the community
Discussion for this compound concentrates in r/longevity and r/Biohackers.
No threads cached yet.
Reddit removed unauthenticated API access, so this section is populated by a build-time script using your own API credentials. Run pnpm fetch:reddit with REDDIT_CLIENT_ID and REDDIT_CLIENT_SECRET set.