What it is
Glutathione is the body's principal intracellular antioxidant, a tripeptide made of glutamate, cysteine and glycine. Injectable forms are widely used in wellness and IV-therapy settings for antioxidant support, detoxification pathways and skin brightening.
In the PeptidesAI encyclopedia it is categorized under immune and skin and anti-aging. Evidence for the skin-lightening claims is weak, and regulators have warned specifically against injectable glutathione marketed for that purpose.
How it's thought to work
Glutathione serves as the main substrate for glutathione peroxidase and related enzymes, neutralizing reactive oxygen species and supporting phase II detoxification conjugation. It also inhibits tyrosinase, the enzyme that makes melanin, which is the rationale behind pigmentation-related claims. Laboratory research links the glutathione system with regulating pheomelanin formation, and exogenous glutathione has been shown to act as a depigmenting agent.
What the research says
Glutathione biochemistry is extremely well characterized. Clinical evidence that injectable supplementation improves outcomes is limited. A 2018 dermatology review found that evidence for intravenous glutathione as a skin-lightening agent rested on a single study with a dubious design, and noted that some national agencies have issued bans or advisories on parenteral glutathione for that purpose. Glutathione is not FDA-approved for these uses.
Reported side effects
Reported side effects include injection site stinging, transient headache and occasional gastrointestinal upset. Serious hypersensitivity reactions have been reported with high-dose IV use, and unregulated injectable products carry sterility and purity risks.
Reconstitution
Glutathione is supplied as a lyophilized (freeze-dried) powder and is typically reconstituted with bacteriostatic (BAC) water before use. It commonly comes in 200 mg, 600 mg and 1200 mg vials. The amount of peptide in the vial is fixed; the water added only changes how concentrated the solution is.
Worked example. A 600 mg vial is 600,000 mcg. Reconstituted with 6 mL of BAC water, that works out to 600,000 mcg ÷ 6 mL = 100,000 mcg/mL. On a U-100 insulin syringe, where each unit is 0.01 mL, each unit holds 100,000 × 0.01 = 1 mg. Use the peptide reconstitution calculator to work out the concentration and units for any vial size and water volume.
Important notes
Glutathione is not FDA-approved for antioxidant or skin-lightening use. Injectable products from unregulated sources carry sterility risks.
Sources
- Glutathione for skin lightening: a regnant myth or evidence-based verity?. Sonthalia S et al. Dermatol Pract Concept, 2018. Review
- Modulating skin colour: role of the thioredoxin and glutathione systems in regulating melanogenesis. Lu Y et al. Biosci Rep, 2021. Review
Frequently asked questions
These questions cover the same ground as the sections above, in a shorter format.
What is glutathione?
The body's principal intracellular antioxidant, a tripeptide of glutamate, cysteine and glycine, also given by injection in wellness and IV-therapy settings.
How is glutathione thought to work?
It serves as the main substrate for glutathione peroxidase and related enzymes, neutralizing reactive oxygen species, and it also inhibits tyrosinase, the rationale behind pigmentation claims.
What does the research on glutathione say?
Its biochemistry is well characterized, but clinical evidence for injectable supplementation is limited, evidence for skin lightening is weak, and it is not FDA-approved for these uses.
What are the reported side effects of glutathione?
Injection site stinging, transient headache and occasional gastrointestinal upset; serious hypersensitivity reactions have been reported with high-dose IV use.
How much is one unit from a 600 mg Glutathione vial?
With 6 mL of BAC water, a 600 mg vial is 100,000 mcg/mL, so one unit on a U-100 syringe (0.01 mL) holds 1 mg.
The full entry, plus the calculator
The PeptidesAI app has the complete encyclopedia entry for Glutathione — one of 70 compounds covered — plus the reconstitution calculator, a dose log and reminders. Free to download on iPhone.
Download on the App Store