| Aliases | GSH |
| Class | Antioxidant tripeptide |
| Molecular weight (Da) | 307.3 |
| Half-life (indicative) | very short (IV ~10 min) |
| Research status | Supplement / cofactor |
Research context (RUO): NAD+ and glutathione are two central molecules in redox biology studied in laboratory research around cellular energy and oxidative stress. Both are supplied solely for in-vitro laboratory research and are not intended for human or animal use.
NAD+ and glutathione in research: redox biology explained
NAD+ and glutathione keep appearing in research into energy, ageing and oxidative stress. They are not peptides, but they belong in the knowledge base because they determine the cell's “redox balance” — the equilibrium between oxidation and rendering it harmless. This page explains in plain language what both do, how they relate, and links to the separate pillars with the details.
What is redox biology? — in plain language
“Redox” is a contraction of reduction and oxidation: the transfer of electrons between molecules. That sounds abstract, but it is the basis of how cells make energy and of how they limit damage from “free radicals”. Two molecules play a leading role in this: NAD+ mainly handles the energy side, glutathione mainly the protection side.
NAD+ — the energy switch
NAD⁺ (nicotinamide adenine dinucleotide) is a coenzyme that carries electrons in the cell's energy factory (the mitochondria). It also feeds enzymes linked to ageing, such as the sirtuins. Research describes NAD+ levels declining with age — one reason the molecule receives so much attention in ageing research.
Glutathione — the master antioxidant
Glutathione is often called the “master antioxidant”. It is a small molecule (a tripeptide) that neutralises reactive oxygen species and thereby protects cells against oxidative stress. Where NAD+ mainly feeds energy production, glutathione clears the by-products of that production — the two complement each other.
How they are connected
Making energy and clearing damage are two sides of the same coin. The more active the energy metabolism, the more protection is needed. That is why NAD+ and glutathione are often studied together in research, together with the mitochondrial peptides that act on the same energy metabolism. The whole falls under the broader longevity research.
What the NAD+ research in humans shows
NAD+ itself is too large and too unstable to be absorbed well as a standalone compound; research therefore focuses on precursors. In a randomised, placebo-controlled crossover study in 24 adults aged 55 to 79, 500 milligrams of nicotinamide riboside twice daily for six weeks raised NAD+ levels in white blood cells by about sixty percent compared with placebo. Blood pressure fell slightly on average without reaching statistical significance; in the subgroup with an elevated baseline, systolic pressure was about nine millimetres of mercury lower after the treatment period. Tolerability was good and no serious adverse events occurred.
What the glutathione research in humans shows
With glutathione the limiting step is not uptake of the molecule but its synthesis. The building blocks glycine and cysteine become scarcer with age, and that is precisely what the GlyNAC studies target. In a randomised study in 24 older adults aged 61 to 80, glutathione levels in red blood cells were at baseline about seventy percent lower than in young controls. After sixteen weeks of glycine plus N-acetylcysteine they rose back to the level of the young group, while two independent markers of oxidative stress fell by more than seventy percent. In the placebo group none of these values changed.
| Feature | NAD+ system | Glutathione system |
|---|---|---|
| Core role | Electron transfer and energy | Neutralising oxidants |
| Limiting step | Salvage pathway via NAMPT | Synthesis from cysteine and glycine |
| What is given in studies | Precursors such as NR and NMN | Building blocks such as glycine and NAC |
| Measured in | Whole blood and white blood cells | Red blood cells, GSH-GSSG ratio |
Why the two systems are not separate from each other
The link is NADPH. Glutathione does its work by oxidising itself; to become usable again it has to be reduced by glutathione reductase, and that enzyme runs on NADPH. NADPH in turn comes from the pentose phosphate pathway, which starts from the same nicotinamide pool. If the NAD supply drops, the capacity to recycle glutathione drops indirectly as well. Total glutathione may then still look normal while the ratio between the reduced and the oxidised form has already shifted. This is also why both molecules often reappear together in research into combinations.
Where the measurement errors sit
NAD+ breaks down in a blood tube within minutes if the sample is not cooled and stabilised immediately, and glutathione oxidises on contact with air. Both assays are therefore more sensitive to sample handling than to the treatment itself. A second pitfall is the compartment: NAD+ in whole blood, in white blood cells and in muscle tissue does not follow the same curve, and studies measuring different compartments cannot simply be laid side by side. Anyone comparing results therefore looks first at the sample type and the processing time, and only then at the reported change.
Quality & purity
Every relevant batch is independently HPLC-tested by an external laboratory; the CoA is publicly verifiable per batch. See also why we rejected a batch.
Frequently asked questions
Are NAD+ and glutathione peptides?
NAD+ is a coenzyme and glutathione a tripeptide antioxidant. Neither is a classic research peptide, but they belong in the knowledge base because they are central to redox and energy biology.
What exactly does NAD+ do?
It carries electrons in the mitochondria (energy production) and feeds enzymes such as sirtuins. In research, levels decline with age.
Why is glutathione called the master antioxidant?
Because it plays a central role in neutralising reactive oxygen species and protecting cells against oxidative stress.
Why are they studied together?
Energy production (NAD+) and protection against its by-products (glutathione) are closely linked; researchers therefore often view the redox balance as a whole.
May I use these substances?
No. NAD+ and glutathione are supplied solely for in-vitro laboratory research (RUO), not for human or animal use.
Read more & research at Peplife
- NAD+ research · Glutathione research
- Mitochondrial peptides
- Longevity peptides (hub)
- View all anti-aging peptides
Sources: NAD+ metabolism & mitochondria, npj Metabolic Health (2025) · Glutathione & redox homeostasis (PMC)
Research Use Only. All products are supplied exclusively for in vitro laboratory research. Not intended for diagnostic or therapeutic use in humans or animals, and not approved by the EMA or FDA.
NAD+ and glutathione HPLC-tested by an external laboratory, CoA per batch verifiable and discreet EU shipping.