NMN and Cardiovascular Research

What this page covers

This page evaluates human evidence on blood pressure, arterial stiffness (pulse wave velocity), endothelial function, and cardiovascular-relevant lipid markers. It does not evaluate cardiovascular disease outcomes — no trial reviewed here measured heart attack, stroke, or any diagnosed cardiovascular event, because none was designed or large enough to do so.

Arterial stiffness: a null primary finding

A 12-week trial specifically designed to test NAD+ metabolism and arterial stiffness found that pulse wave velocity — the trial's central measure of arterial stiffness — trended lower in the NMN group but did not reach statistical significance.[1] This is the most direct test of arterial stiffness among the trials reviewed here, and its primary result was null.

Blood pressure: a modest, preliminary pooled signal

A 2026 meta-analysis pooling 10 randomized trials and 349 participants found a small but statistically significant reduction in diastolic blood pressure (weighted mean difference −2.15 mmHg) associated with NMN supplementation.[2] Systolic blood pressure reduction was not significant across the full pooled population, but reached significance in the subgroup aged 60 and older (weighted mean difference −3.94 mmHg).[2] The review's own authors describe this evidence as "preliminary and suggestive," explicitly calling for larger, longer, higher-quality trials before firmer conclusions can be drawn.[2] A separate paper, primarily a mechanistic study in mice and cells, included a small human pilot component (NCT04903210): a randomized, open-label trial comparing oral NMN plus lifestyle modification (n=9) against lifestyle modification alone (n=10) in hypertensive patients, verified directly against the primary full text.[3] At 6 weeks, the NMN group showed a systolic blood pressure reduction of 6.11 mmHg and a diastolic reduction of 3.56 mmHg versus the lifestyle-only group, alongside a 0.6% increase in flow-mediated dilation and a 116.66 cm/s decrease in brachial-ankle pulse wave velocity.[3] These are real, directly-verified numbers — but from an open-label trial with no placebo arm and only 19 completing participants, a design that cannot rule out expectation or lifestyle-adherence effects the way a blinded, placebo-controlled trial can.

Individual-trial lipid and blood-pressure findings

One high-dose (2,000 mg/day), industry-funded trial reported significant reductions in diastolic blood pressure, total cholesterol, and non-HDL cholesterol versus placebo over 28 days.[4] This is a single trial's finding, not yet independently replicated, and should be weighed alongside the broader pooled evidence above rather than treated as a settled effect on its own.

Endothelial function

No blinded, placebo-controlled human trial identified for this hub directly measured endothelial function (for example, flow-mediated dilation) as a primary outcome; the one FMD figure available comes from the small, open-label, non-placebo-controlled pilot described above. This remains a genuine evidence gap for a properly controlled test of the question.

What this evidence does not support

This hub does not describe NMN as "heart healthy," and does not imply that NMN prevents or treats cardiovascular disease. The strongest cardiovascular signal identified — a modest pooled blood-pressure reduction — comes from secondary endpoints or small/open-label studies in most of the underlying trials, is explicitly labeled preliminary by the meta-analysis authors themselves, and has not been tested against any actual cardiovascular disease outcome.

Related reading

For the full trial-by-trial breakdown, see NMN Human Clinical Trials. For NAD+'s role in mitochondrial and cellular energy metabolism, see NAD+, Mitochondria, and Cellular Energy.