A Summary of a Nicotinamide Mononucleotide (NMN) Clinical Study by Igarashi et al. (2022)

Reviewed by John Cutts, Ph.D. | Research & Development

Overview

The following summary reviews a clinical study examining the effects of oral nicotinamide mononucleotide (NMN) supplementation on blood NAD⁺ levels and age-related physiological outcomes, including muscle strength and performance, in healthy older men. NMN is an intermediate metabolite in the NAD⁺ biosynthesis pathway and is present in small amounts in foods such as edamame, broccoli, and meat.

Summary

Chronic nicotinamide mononucleotide supplementation elevates blood nicotinamide adenine dinucleotide levels and alters muscle function in healthy older men

Published in: npj Aging

Study Design: Randomized, double-blind, placebo-controlled, parallel-group trial

Participants: 42 healthy Japanese men aged 65 years and older (BMI 22–28 kg/m², nonsmokers, without active disease); 21 per group at baseline. Due to a supplement distribution error at the 6-week visit, data from 22 participants were excluded from the 12-week analysis, leaving 10 per group for the full study duration.

Dose: 250 mg NMN once daily for up to 12 weeks (or matching placebo)

Outcome Measures: Whole blood NAD⁺ and NAD⁺-related metabolites (NMN, NR, NAMN, NAR, NA, NAM) by LC-MS/MS; skeletal muscle mass index (SMI) and segmental lean mass by bioelectrical impedance analysis (BIA); gait speed (10-meter walk test); grip strength (hand dynamometer); 30-second chair-stand test; visceral fat area and CT liver/spleen ratio; HOMA-IR; HbA1c; fasting blood glucose

What Was Studied: Researchers investigated whether daily oral NMN supplementation could elevate whole blood NAD⁺ concentrations and alter physiological measures associated with aging in healthy older men. The primary objective was to assess the effect of 12 weeks of NMN supplementation on blood NAD⁺ levels and body composition, including skeletal muscle mass index. Secondary objectives included evaluation of muscle strength and performance indicators such as gait speed and grip strength, as well as fat mass distribution, markers of insulin sensitivity, and exploratory measures of sensory, vascular, and cognitive function. Participants were assessed at baseline, 6 weeks, and 12 weeks, with blood samples collected for targeted metabolomic analysis and clinical laboratory evaluation.

About the Reviewer

Name & Title: John Cutts, Director of Research at Solaray
Credentials: PhD Pharmacology & Toxicology

Bio: John Cutts, Ph.D. earned his Doctorate of Philosophy in Pharmacology and Toxicology from the University of Alabama at Birmingham and his Bachelors of Science in Chemistry from BYU-Idaho. He has nearly 20 years of experience in the dietary supplement space, with a focus on scientific substantiation, regulatory affairs, and product development. His graduate research centered on the health-related properties of botanical compounds. He currently works in research and development, where he evaluates clinical evidence for dietary supplement ingredients.

Reference

Igarashi M, Nakagawa-Nagahama Y, Miura M, et al. Chronic nicotinamide mononucleotide supplementation elevates blood nicotinamide adenine dinucleotide levels and alters muscle function in healthy older men. npj Aging. 2022;8(1):5. https://pubmed.ncbi.nlm.nih.gov/35927255/

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In double-blind studies, participants and researchers are
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