NR Supplementation Tested as Cardiac Rescue in Systolic Heart Failure Patients
A Phase 1/2 trial tests whether nicotinamide riboside can restore NAD+ balance and improve heart function in systolic HF patients.
Summary
Heart failure is partly driven by mitochondrial dysfunction, which depletes NAD+ and impairs energy production in cardiac cells. This completed Phase 1/2 clinical trial from the University of Washington tested whether nicotinamide riboside, a natural NAD+ precursor, could safely be given to patients with systolic heart failure and reduced ejection fraction. Participants were randomized to NR or placebo, with doses escalated to 1000mg twice daily. The trial builds on promising mouse model data showing that restoring the NADH/NAD ratio improved cardiac function. Primary goals were safety and tolerability, making this an important early-stage human test of an accessible supplement in a serious cardiac condition affecting millions worldwide.
Detailed Summary
Heart failure affects over 64 million people globally and carries a poor prognosis, with mitochondrial dysfunction increasingly recognized as a core driver of cardiac deterioration. When heart muscle cells cannot generate sufficient energy, the organ progressively weakens. One key mechanism involves a disrupted ratio of NADH to NAD+, effectively starving cells of the oxidized form needed for energy metabolism. Correcting this imbalance has become a compelling therapeutic target.
Researchers at the University of Washington designed this randomized, placebo-controlled Phase 1/2 trial to evaluate nicotinamide riboside in patients with systolic heart failure defined by an ejection fraction at or below 40%. NR was chosen because it is an orally bioavailable NAD+ precursor that has demonstrated safety in healthy populations. The dose was escalated to a final target of 1000mg twice daily, representing a clinically meaningful intervention level.
The primary endpoints focused on safety and tolerability rather than efficacy, which is appropriate for this early-phase investigation. Prior preclinical work in mouse heart failure models showed that NAD+ precursor supplementation normalized the NADH/NAD ratio and was associated with measurable improvement in cardiac function, providing the mechanistic rationale for this human study.
This trial represents a critical translational step from bench to bedside. If NR proves safe and well-tolerated in this vulnerable population, it opens the door to larger efficacy trials assessing whether NAD+ restoration can meaningfully improve ejection fraction, exercise capacity, or quality of life in heart failure patients.
Caveats are significant. The trial was early-phase and primarily designed around safety endpoints, not efficacy outcomes. Full results have not been published in a peer-reviewed journal as of this summary. The small sample size typical of Phase 1/2 trials limits generalizability. Additionally, this summary is based on the abstract and registry record only.
Key Findings
- Trial tested NR at up to 1000mg twice daily in systolic heart failure patients with ejection fraction ≤40%.
- Preclinical mouse data showed NAD+ precursor supplementation improved cardiac function by restoring NADH/NAD ratio.
- Phase 1/2 design prioritized safety and tolerability as primary endpoints before efficacy testing.
- Mitochondrial NAD+ depletion is an emerging mechanistic target in heart failure management.
- Completed status suggests NR was sufficiently tolerated to advance the research program.
Methodology
Randomized, placebo-controlled Phase 1/2 trial conducted at the University of Washington enrolling systolic HF patients with ejection fraction ≤40%. NR was uptitrated to 1000mg twice daily with matching placebo comparator. Primary endpoints were safety and tolerability rather than clinical efficacy.
Study Limitations
This summary is based on the abstract and ClinicalTrials.gov registry record only, as the full study data are not openly accessible. The Phase 1/2 design was powered for safety, not efficacy, limiting conclusions about clinical benefit. Small trial size and absence of peer-reviewed publication further constrain interpretation.
Enjoyed this summary?
Get the latest longevity research delivered to your inbox every week.