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Glutathione and NAD+ are both sold as “longevity” IVs and both live in the world of cellular redox, which is why they get lumped together. But they do genuinely different jobs — one mops up oxidative damage, the other fuels the reactions that produce energy and drive repair — and only one of them is actually a peptide.
Research reference only. Not medical advice, prescribing guidance, or a product recommendation.
| Dimension | Glutathione | NAD+ |
|---|---|---|
| What it is | A tripeptide (γ-Glu-Cys-Gly) — a true peptide | A coenzyme (dinucleotide) — not a peptide |
| Primary role | Master antioxidant / redox buffer | Metabolic redox cofactor + signaling substrate |
| What it does | Neutralizes reactive oxygen species; detox conjugation | Carries electrons; powers sirtuins and PARP-mediated DNA repair |
| Key chemistry | Cysteine thiol donates electrons; cycles GSH ⇄ GSSG | Cycles NAD+ ⇄ NADH in energy metabolism |
| Grey-market use | Antioxidant, detox, and skin-lightening (weak evidence) | Energy, longevity, “anti-aging” IVs |
| Research focus | Oxidative stress, detoxification, skin | Mitochondrial energy, sirtuin longevity signaling, aging |
| Status | Supplement / reagent — not FDA-approved for these uses | Research reagent / investigational — not FDA-approved |
| Molecular weight | 307.3 Da | 663.4 Da |
Glutathione (GSH) is the cell’s principal antioxidant — and, unlike NAD+, it is a genuine peptide: a tripeptide of glutamate, cysteine, and glycine, joined through an unusual γ-glutamyl bond that resists ordinary peptidases. Its working end is the cysteine thiol, which donates electrons to neutralize reactive oxygen species and serves as a substrate for the enzymes that conjugate and clear toxins, cycling between reduced (GSH) and oxidized (GSSG) forms. On the grey market it is sold as an injectable and IV for antioxidant support and detox, and especially for skin lightening — a use marketed heavily on thin, inconsistent clinical evidence.
NAD+ is not a peptide at all but a coenzyme, and its job is not to neutralize damage but to run the machinery. Every cell uses it to carry electrons through energy metabolism, and two enzyme families central to aging depend on it: sirtuins, for stress-resistance and longevity signaling, and PARPs, for DNA repair. Cellular NAD+ declines with age, which is why restoring it (directly or via precursors) is a longevity theme and why NAD+ IVs are marketed for energy and “anti-aging.” So the two are complementary rather than competing: glutathione defends the cell against oxidative damage; NAD+ powers the reactions that generate energy and maintain the genome. Both decline with age, both are sold as injectables, and neither is FDA-approved for these uses.
Same broad theme, different roles. Glutathione is a tripeptide antioxidant — it neutralizes reactive oxygen species and supports detoxification, and its most-marketed use (skin lightening) rests on weak evidence. NAD+ is a metabolic coenzyme — not a peptide — that fuels energy production and the sirtuin/PARP machinery tied to aging. They are complementary parts of cellular redox, not substitutes, and neither is FDA-approved for the antioxidant, longevity, or cosmetic uses they are sold for. This page is a research and educational reference.
Glutathione is a tripeptide antioxidant that neutralizes reactive oxygen species and supports detoxification. NAD+ is a coenzyme (not a peptide) that carries electrons in energy metabolism and powers sirtuins and DNA-repair enzymes. One defends against oxidative damage; the other fuels metabolic and repair machinery.
Yes. Glutathione is a genuine tripeptide (γ-Glu-Cys-Gly). NAD+ is a dinucleotide coenzyme, not a peptide — it is catalogued alongside peptides for its metabolic and longevity relevance.
Glutathione is marketed heavily for skin lightening, but the clinical evidence is weak and inconsistent and its safety for that use is unclear. This page is a research and educational reference, not medical advice.
No. Glutathione is sold as a supplement/reagent and NAD+ as a research reagent and investigational therapeutic; neither is FDA-approved for the antioxidant, detox, longevity, or cosmetic uses they are marketed for. This page is a research and educational reference.
Mechanism, evidence, and trade-offs between Glutathione and NAD+ — citation-backed answers grounded in PubMed, PubChem, and ClinicalTrials.gov.