NMN

Nicotinamide Mononucleotide · NAD+ precursor

NAD⁺ precursor: more cellular energy and a possible anti-aging effect.

TypeSupplement / dietary

The grade answers: What does the human evidence support for: NAD⁺ and metabolic support?

Structure · PubChem

Grade

Moderate

The grade rates evidence quality — it is not advice to take or buy.

Class: Cellular metabolism
Primary use: NAD⁺ and metabolic support
Evidence strength: medium
Last reviewed: 2026-06-15

Not EU authorised

Not authorised as a novel food in the European Union. Sale as a supplement in Italy is not permitted. You will still find it online: that means the seller is operating outside the rules, not that the rules don't exist.

Source: Non autorizzato come novel food UE. Parere EFSA positivo (mag 2026) su un singolo prodotto; autorizzazione della Commissione non ancora concessa

Attention

Evidence

How it's sold: The NAD+ precursor that reverses cellular aging.
What the studies show: Human trials reliably raise blood NAD+. Whether raising it changes how you age has not been shown — those are two different questions, and only the first has been answered.

The attention level is our editorial estimate of public interest, not a measurement. Evidence is derived from the A–F grade.

Bottom line

Reliably raises blood NAD⁺ in humans; a real clinical benefit is biologically plausible but not yet proven — hence grade B.

What the evidence says

Phase I/II human trials consistently raise blood NAD⁺ (+40–80%), but with small samples, short follow-up and surrogate outcomes. Hard clinical endpoints are not yet demonstrated.

Key studies

[1]
12-week NMN in older adults: blood NAD, walking speed and sleep (GeroScience, 2024) · RCT
Randomised, placebo-controlled, double-blind, 60 participants. Blood NAD rose and walking speed was maintained — maintained, not improved.
PMID 38789831 — read the article ↗
[2]
NMN and muscle insulin sensitivity in prediabetic women (Science, 2021) · RCT
10 weeks, randomised, placebo-controlled, postmenopausal women with prediabetes. Muscle insulin sensitivity improved; other metabolic measures did not shift.
PMID 33888596 — read the article ↗
[3]
NMN in healthy middle-aged adults, dose-dependent (GeroScience, 2023) · RCT
80 adults, multicentre, dose-ranging. Animal data on healthspan and lifespan does not transfer automatically to humans — the paper says so itself.
PMID 36482258 — read the article ↗

See all studies on PubMed ↗

Mechanism

Direct precursor of NAD⁺ in the salvage pathway; NAD⁺ is a cofactor of sirtuins and PARPs, involved in DNA repair and metabolic regulation.

Safety

Good short-term tolerability in available RCTs: no severe adverse events reported. Long-term safety data are lacking.

Dosage context

In studies: 250–900 mg/day for 8–24 weeks. Higher doses did not show proportionally greater benefit.

Examples of application

Taken as a morning capsule, often within a NAD⁺-support routine.
Used in defined cycles with periodic reassessment, not indefinitely.
Treated as an add-on to sleep, exercise and diet — which matter more.

From the field

We follow NMN trial by trial and we know how it's sold: the NAD⁺ numbers are real, but the leap 'more NAD⁺ = live better' is not yet proven in humans. Hence grade B.

Related molecules

ResveratrolC SpermidineB

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How we assign grades → Method