Human randomized trial
The differential impact of three different NAD+ boosters on circulatory NAD and microbial metabolism in humans
Stefan Christen, Karine Redeuil, Laurence Goulet, Maria-Pilar Giner, Isabelle Breton, Riccardo Rota, Adrien Frézal, Atiye Nazari, Pieter Van den Abbeele, Jean-Philippe Godin, Sophie Nutten, Bernard Cuenoud
Nature Metabolism · 2026 · 8(1):62–73
Study at a glance
- Design
- Randomized, open-label, placebo-controlled four-arm trial lasting 14 days, supplemented by ex vivo gut-fermentation and whole-blood experiments.
- Population or model
- Healthy adults aged 18–50 years with BMI 18.5–27 kg/m²; the modified intention-to-treat population had a mean age of 34.7 years and included 32 men and 33 women.
- Sample size
- 67 randomized; 65 analyzed (NR n=16, NMN n=15, nicotinamide n=17, placebo n=17)
- Intervention
- Daily oral NR 1 g, NMN 1 g, nicotinamide 0.5 g, or placebo for 14 days.
- Publication type
- Randomized controlled trial
- Evidence class
- human-study
- Research area
- NAD+ precursor metabolism and microbiome
- Trial registration
- NCT05517122
Study endpoints
- Primary: change from baseline in whole-blood NAD+ after 14 days
- Acute four-hour and chronic NAD+ metabolome responses
- Exploratory plasma and urine metabolomics
- Adverse events and ex vivo microbiome and whole-blood metabolism
Plain-language summary
Key findings
Limitations
Funding and transparency
Funding
Not stated in the publication.
Competing interests
Stefan Christen, Karine Redeuil, Laurence Goulet, Maria-Pilar Giner, Isabelle Breton, Riccardo Rota, Adrien Frézal, Atiye Nazari, Jean-Philippe Godin, and Sophie Nutten were employees of Nestlé Research. Bernard Cuenoud was an employee of Nestlé Health Science. Pieter Van den Abbeele was an employee of Cryptobiotix SA.
HealthspanX observation
The authors were employees of Nestlé Research, Nestlé Health Science, or Cryptobiotix SA; the proposed gut-microbiome mechanism was supported mainly by ex vivo experiments.
Interpretive weight
Moderate
Randomization, a placebo arm, and a prespecified NAD+ biomarker strengthen the result, but the trial was open-label, short, and not designed to show clinical outcomes.
This record summarizes a publication; it is not medical advice or a claim that a HealthspanX product reproduces the study's results. Report a correction.