Coenzyme (not a peptide)

NAD+

A central metabolic coenzyme studied in ageing and metabolism.

Human trials (mixed outcomes)

At a glance

Sequence
Nicotinamide adenine dinucleotide (dinucleotide coenzyme)
Molecular weight
CAS
Class
Coenzyme (not a peptide)
Aliases
NAD, nicotinamide adenine dinucleotide

Overview

Not a peptide — a coenzyme essential to energy metabolism and redox reactions.

Levels decline with age; boosting via precursors (NR/NMN) is heavily researched, with mixed human outcomes.

Mechanism

Serves as an electron carrier in metabolism and a substrate for sirtuins and PARPs; precursor supplementation raises circulating NAD+.

Research

What the studies show

PRISMA systematic review of NAD+ supplementation

Various · ScienceDirect · 2026 · Systematic review

Finds biochemical NAD+ engagement is reliable but downstream clinical outcomes in humans are mixed and inconsistent.

Clinical evidence for NAD+ precursors to slow aging

Various · Review · 2025 · Review

Synthesises recent NR/NMN trials across metabolism, cognition and kidney disease.

Qualia NAD+ RCT

Various · medRxiv · 2025 · RCT

A randomised placebo-controlled study reporting raised blood NAD+ and some improved aging symptoms; preprint, not yet peer-reviewed.

Meta-analysis of NMN RCTs

Chen F, et al. · Current Diabetes Reports · 2024 · Meta-analysis

Meta-analysis of NMN RCTs on glucose and lipid metabolism in adults.

NAD+ augmentation in overweight/older adults

Pencina KM, et al. · J Clin Endocrinol Metab · 2023 · Human

NAD+ augmentation in overweight/older adults; characterises physiological response.

Evidence summary

Supported by genuine human clinical trials and a well-established safety profile, with reliable biochemical effects and a rapidly expanding evidence base across metabolism and healthy ageing. One of the most actively studied compounds in the longevity field.