Taking NAD+ supplements slows the progression of neurodegenerative diseases like Alzheimer's and Parkinson's.
See the scientific wording
NAD+ supplementation improves outcomes in neurodegenerative diseases.
There's disagreement
Randomized trialsThe 5 studies we reviewed point in different directions — there's no clear consensus.
What the research says
5 studies reviewedSupporting (3)
Randomized Controlled TrialHuman2025
This study tested a NAD+ booster in people with early memory problems. It didn't improve memory or thinking, but it did lower a blood marker linked to Alzheimer's. So it shows some potential, but not a clear benefit yet.
Randomized Controlled TrialHuman2022
This study gave people with Parkinson's a supplement that boosts a key energy molecule (NAD) in the brain, and it was safe and seemed to help a little, but it wasn't a big enough study to say for sure if it slows the disease.
Supplementation with NAD+ Precursors for Treating Alzheimer’s Disease: A Metabolic Approach
Systematic ReviewReview2024
This review of studies found that NAD+ supplements like nicotinamide riboside improved brain markers and thinking in some mice and a few people with Alzheimer's, suggesting they might help slow the disease.
Contradicting (2)
Randomized Controlled TrialHuman2026
The study gave a NAD+ booster to people with early memory problems, and while it raised NAD+ levels, it didn't improve memory or brain function, so it doesn't support the idea that NAD+ supplements help with Alzheimer's.
Supplementation with NAD+ and Its Precursors to Prevent Cognitive Decline across Disease Contexts
Narrative ReviewReview2022
The study found that NAD+ supplements helped animals but didn't help people with dementia or healthy people think better, so the claim isn't supported by the evidence.
Quality-weighted scoring: we follow the GRADE framework — each study is rated High, Moderate, Low, or Very Low based on study design, methodology rigor, and risk of bias. A single high-quality RCT can outweigh several weaker observational studies.
Scores reflect study quality, not just count.
Score breakdown, mechanism chain, raw evidence, ideal studies needed & 3 supporting, 2 contradicting studies
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