# NAD+ precursors taken by mouth

Source: https://onco.cc/technologies/rejuv-frontier-nad-precursors/  
OnCo record `rejuv-frontier-nad-precursors` (Technology). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

NAD+ falls with age, and swallowing a precursor raises it in the blood. That much is established. Whether raising it does anything for a person who has had cancer is not. The one B3 compound with a real cancer result is plain nicotinamide, for preventing skin cancers in people who keep getting them, which is a different claim entirely.

## Summary

Nicotinamide riboside and nicotinamide mononucleotide are precursors of nicotinamide adenine dinucleotide. They raise blood NAD+ reliably: in NR-SAFE, a randomised double-blind trial of 20 people with Parkinson's disease given 1,500 mg twice daily for four weeks, there were no moderate or severe adverse events and blood NAD+ rose up to fivefold. That is a safety and pharmacokinetic result, not an efficacy one, and the trial was in Parkinson's disease, not cancer.

The compound in this family with a hard clinical result is nicotinamide itself. In the ONTRAC trial, 386 people who had had at least two non-melanoma skin cancers in the previous five years took nicotinamide 500 mg twice daily or placebo for 12 months. New non-melanoma skin cancers were 23 per cent lower (95% CI 4 to 38, P = 0.02), with no noteworthy difference in adverse events and no benefit after the drug was stopped. That is a chemoprevention result in a high-risk skin group; it is not evidence that nicotinamide, or any NAD+ precursor, slows ageing or repairs anything after chemotherapy.

There is no randomised trial of an NAD+ precursor in cancer survivors for recovery, fatigue or biological age. There is also an unresolved laboratory question about whether raising NAD+ favours tumour cells, which NAD-dependent repair enzymes also use; no human data settle it either way. The honest summary is that these are well tolerated, do what they say to a blood level, and have never been shown to do anything a survivor would notice.

## Fields

- Kind: Technology
- Status: phase-2
- Last checked: 2026-10-02
- Tags: rejuvenation; survivorship; evidence:insufficient; supplement
- Principle: NAD+ is the cofactor for sirtuins, PARPs and CD38 and falls with age in several tissues. Oral precursors enter the salvage pathway and raise NAD+ in blood and some tissues; the hypothesis is that restoring the cofactor restores sirtuin-dependent repair and mitochondrial function.
- Strengths: Oral dosing reliably raises blood NAD+, demonstrated in randomised trials; Well tolerated at high doses over weeks; Plain nicotinamide has a positive randomised chemoprevention result in high-risk skin cancer
- Limitations: No randomised trial in cancer survivors for any rejuvenation outcome; Raising a blood level is not an outcome; Unresolved laboratory question about NAD+ availability to tumour cells; Marketed with claims the trials do not support

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Nicotinamide_riboside
- Brakedal et al., NR-SAFE: a randomized, double-blind safety trial of high dose nicotinamide riboside in Parkinson's disease (Nat Commun 2023): https://doi.org/10.1038/s41467-023-43514-6
- Chen et al., A phase 3 randomized trial of nicotinamide for skin-cancer chemoprevention, ONTRAC (NEJM 2015): https://doi.org/10.1056/NEJMoa1506197

## Connected records

- technologies: [Intravenous NAD+ drips](https://onco.cc/technologies/rejuv-frontier-nad-infusions/), [Survivorship care and late-effects surveillance](https://onco.cc/technologies/survivorship-care-plan/), [What actually works after treatment](https://onco.cc/technologies/rejuv-frontier-what-works/)
- fronts: [Recovery & Rejuvenation](https://onco.cc/fronts/rejuvenation/), [Supportive Care & Survivorship](https://onco.cc/fronts/supportive-care/)
- drugs: [Nicotinamide](https://onco.cc/drugs/nicotinamide/)
- terms: [Late effects and survivorship toxicity](https://onco.cc/terms/late-effects/)
- bottlenecks: [Survivorship and late effects are neglected](https://onco.cc/bottlenecks/b-survivorship/)

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