Digestery
Longevity supplements › NMN and Aging › Studies

Trial, not randomized · measured other health measures

A 4-week no-placebo NR trial in 8 people with leg artery disease reported gains

Szarvas and colleagues · The Journal of pharmacology and experimental therapeutics · 2025

Original title: Effects of NAD+ supplementation with oral nicotinamide riboside on vascular health and cognitive function in older adults with peripheral artery disease: Results from a pilot 4-week open-label clinical trial.

Under review. A person has not yet checked this summary against the paper. It is written from the PubMed abstract. Until a person checks it, search engines are asked not to list this page.

What the study found

Points to benefit

Authors report a positive trend in artery cell function, improved brain blood flow response in one area, and better thinking scores across several areas after NR. No numbers are given in the abstract.

The study at a glance

Type of study
Trial, not randomized
Who or what was studied
8 people · Older adults with peripheral artery disease (clogged leg arteries)
What was tested
NR for 4 weeks, no placebo group (open label)
What it measured
Several kinds of outcomes
How long
4 weeks
Trial registration
NCT06534944
Who has a stake
Company stake
One author has research funding or consulting fees from Elysium Health, Metro International Biotech, Pfizer and others.
Journal
The Journal of pharmacology and experimental therapeutics, 2025
Source
PubMed record 40479886. This page is based on the abstract only.

How much this study counts

  • –Not randomized: the groups may differ in ways that affect the result.
  • ✓Compared with a placebo, a dummy treatment.
  • –Small: 8 people. Small trials can miss real effects or find chance ones.
  • –Short: 4 weeks. Longer-term effects are unknown.
  • •Measured several kinds of outcomes.
  • –Company stake: One author has research funding or consulting fees from Elysium Health, Metro International Biotech, Pfizer and others.
  • •Summarized from the PubMed abstract only. The full paper may hold details the abstract leaves out.

✓ Strength– Limit• Note

These points come from fixed rules about the type of study, its size and length, what it measured, and who has a stake. Every study on Digestery gets the same rules.

Where this study sits

Each dot is one on-topic paper on this question. Steps near the top answer the question more directly.

↑ Stronger evidence

  1. Trials in people: aging and age-related decline

    0

    Not done yet. This is the step that would answer the question.

  2. Trials in people: other measures

    9

    3 benefit, 2 mixed, 4 no difference

    ↑ This study is the ringed dot

  3. Trials in people: lab tests or safety

    7

    4 benefit, 1 mixed, 2 no difference

  4. Population studies

    0

    None among the papers we read.

  5. Blood levels and genes

    0

    None among the papers we read.

  6. Animals

    6

    5 benefit, 1 mixed

↓ Weaker evidence

  • Points to benefit
  • Mixed
  • No difference
  • No direction
  • Points to harm

How it fits with the other research

The short answer to “Does NMN slow aging?”

Not shown in people so far.

Confidence: very low. Based on 29 on-topic papers.

Read the full answer

Of the other 8 papers on the same step: 2 benefit, 2 mixed, 4 no difference. This one found benefit.

Other papers on the same step

See all 29 studies on this question

How this page was made

Label

First read of the abstract
Claude Sonnet
Independent second read
Claude Haiku
Differences settled
The two reads differed. The reviewer checked the abstract and kept the first read. Claude Opus 5.5.
Headline
Claude Sonnet, from the checked study record. A script checked its numbers and wording.
Numbers
Checked against the abstract by a script
“How much this study counts”
Fixed rules, the same for every study
Source check by a person
Not yet. Required before search engines may list this page.

Spot an error? Email a flag with a link to your source, or use the form on the question page.