Humanin vs NAD+
Humanin (Mitochondrial-derived peptide) and NAD+ (Cellular coenzyme (dinucleotide)) are documented as co-studied in the PeptiDex library. This page puts the two entries side by side on class, molecular weight, half-life, origin, mechanism and studied research areas — every value taken from the entry it belongs to.
Why these two are co-studied
Cross-referenced for research context — not a usage or combination recommendation.
At a glance
| Attribute | Humanin | NAD+ |
|---|---|---|
| Compound class | Mitochondrial-derived peptide | Cellular coenzyme (dinucleotide) |
| Research category | Longevity & Cellular | Longevity & Cellular |
| Length (amino acids) | 24 amino acids | Not documented |
| Molecular weight | 2687 g/mol (approx., 24-aa form) | 663.43 g/mol (free acid) |
| Half-life | Not documented | Not documented |
| Origin | Humanin is a small mitochondrial-derived peptide encoded within the mitochondrial 16S ribosomal RNA gene (MT-RNR2). It was identified in the early 2000s from surviving neurons in Alzheimer's disease brain tissue and is one of the first characterized mitochondrial-derived peptides. | Nicotinamide adenine dinucleotide (NAD+) is a naturally occurring coenzyme present in all living cells, first described in the early 20th century in the context of fermentation and cellular respiration. It is not a peptide but a dinucleotide composed of a nicotinamide moiety and an adenine moiety joined through ribose and phosphate groups. |
“Not documented” means the PeptiDex entry records no value for that field. Nothing on this page is estimated, and no figure is carried over from one compound to the other.
How Humanin works
Humanin is reported to have cytoprotective and anti-apoptotic effects. Described mechanisms include interaction with pro-apoptotic Bcl-2 family proteins (such as Bax and BID) and signaling through a cell-surface receptor complex, with downstream effects on cell survival pathways. It has also been studied for roles in metabolic regulation and insulin sensitivity. Both a 24-amino-acid form (mitochondrial translation) and a 21-amino-acid form (cytoplasmic translation) have been described.
How NAD+ works
NAD+ functions as a central redox cofactor, cycling between its oxidized (NAD+) and reduced (NADH) forms to shuttle electrons in glycolysis, the citric acid cycle, and oxidative phosphorylation. Beyond redox chemistry, NAD+ is a required substrate for enzymes that consume it, including sirtuins (NAD+-dependent deacylases), poly(ADP-ribose) polymerases (PARPs) involved in DNA repair, and CD38. Cellular NAD+ levels have been reported to decline with age in various tissues, which is a focus of aging research. It is synthesized de novo from tryptophan and through salvage pathways from precursors such as nicotinamide, nicotinic acid, and nicotinamide riboside.
Mechanistic descriptions reflect published research-literature understanding and are quoted from each compound's own entry. Much peptide research is preclinical (in-vitro or animal-model); mechanism in humans may differ and is not established for many compounds.
Where each one appears in the literature
The research contexts each entry documents. Listing a research area is not a claim of efficacy or a therapeutic indication, and the two lists are not scored against each other.
Humanin
NAD+
What sets each apart
Humanin
Humanin is a naturally encoded mitochondrial-derived signaling peptide focused on cytoprotection and metabolism, distinct from the synthetic mitochondria-targeting SS-31 and from immune or pineal peptides.
NAD+
Unlike the peptides in this category, NAD+ is a small-molecule coenzyme central to redox metabolism rather than a signaling peptide, and it is studied primarily via precursor supplementation.
Frequently asked questions
What is humanin?
Humanin is a 24-amino-acid mitochondrial-derived peptide (MDP) encoded within the 16S rRNA region of mitochondrial DNA, discovered in 2001. It is the founding member of the mitochondrial-derived peptide family and is studied for cytoprotective, neuroprotective, and metabolic effects.
What is the sequence and molecular weight of humanin?
Humanin's sequence is MAPRGFSCLLLLTSEIDLPVKRRA, a 24-residue peptide with an approximate molecular weight of about 2687 Da. Some research analogs (e.g. HNG, with a Ser14Gly substitution) are more potent variants used in studies.
What is humanin studied for?
Preclinical research has examined humanin for neuroprotection against amyloid-beta toxicity, cardioprotection in ischemia-reperfusion injury, insulin sensitization via central STAT3 signaling, and anti-apoptotic effects through BAX antagonism. These are cell and animal findings, not established human therapies.
What is NAD+ and what is it studied for?
NAD+ (nicotinamide adenine dinucleotide) is a coenzyme central to cellular energy metabolism, redox reactions, and as a substrate for sirtuins and PARP enzymes involved in DNA repair. It is studied in models of aging, mitochondrial function, metabolic decline, and neuroprotection, where tissue NAD+ levels fall with age. It is a naturally occurring coenzyme, not a peptide.
Is NAD+ a peptide?
No. NAD+ is a dinucleotide coenzyme composed of two nucleotides (one bearing adenine, the other nicotinamide) joined through phosphate groups, not a chain of amino acids. It is grouped in longevity research catalogs alongside peptides because of its role in aging and mitochondrial studies, but it is a distinct chemical class.
How does NAD+ differ from precursors like NMN and NR?
NMN (nicotinamide mononucleotide) and NR (nicotinamide riboside) are biosynthetic precursors that cells convert into NAD+, whereas NAD+ is the finished coenzyme. Precursors are commonly studied as oral routes to raise intracellular NAD+, while NAD+ itself is studied via IV or subcutaneous routes in research settings. Direct cellular uptake of intact NAD+ is a subject of ongoing research.
Answers are the ones published on each compound's own PeptiDex entry. They are educational summaries of research-literature context and are not medical advice.