NR (Nicotinamide Riboside)

What it does

Nicotinamide riboside is a form of vitamin B3 that cells convert directly into NAD+, a coenzyme central to energy metabolism that declines with age. Raising NAD+ is the one effect human trials consistently confirm; whether that translates into health benefits is still unproven.

What the research says

• Reliably raises blood NAD+ levels

  Evidence: strong. Multiple human trials show 300-1000 mg/day raises blood NAD+ by roughly 50% to over 140% versus baseline.

• Improves fatigue, sleep, and depression scores in long COVID

  Evidence: weak. A 58-person RCT (eClinicalMedicine, 2025) found within-group symptom improvements alongside higher NAD+; small and company-sponsored.

• Does NOT slow Parkinson's disease progression

  Evidence: strong. The 410-person NOPARK trial (JAMA, 2026) found no clinical benefit after one year, with the NR group scoring slightly worse than placebo.

The pharmacology is proven (NAD+ rises) but the clinical story is sobering: the largest rigorous trial, NOPARK, failed its primary endpoint, and positive signals come from small or industry-linked studies. More human evidence exists than for NMN, yet no demonstrated longevity benefit.

What the experts say

Every position links to its source. We include skeptics alongside supporters.

• Charalampos Tzoulis

  “Our results therefore do not support NR as a treatment to slow Parkinson's disease.”

  Source, 2026-10-08 Lead investigator of the 410-person NOPARK trial; concluded NR clearly increased NAD metabolism but this did not translate into clinical improvement in early Parkinson's disease.

Is it worth it?

Mid-priced and safe, but you are paying for a biomarker (NAD+) with no proven clinical payoff. Worth it mainly for people who value the NAD+ mechanism and can afford a supplement whose flagship disease trial just failed.