What Glutathione is
Glutathione is the body's principal intracellular antioxidant, a tripeptide of glutamate, cysteine, and glycine. Compounded injectable glutathione is common in antioxidant and skin protocols, typically a few hundred milligrams a few times per week subcutaneously or intramuscularly.
What we do not know
- Oral bioavailability is contested rather than settled: one randomized trial reported increased body stores, another found no change in oxidative stress markers. Both are cited on this page.
- Skin lightening is the most common reason for injected use and has weak trial support. Regulators including the FDA have warned specifically about injectable skin-lightening products.
- Whether raising circulating glutathione raises it inside the cells where it acts is the unresolved question underneath all of it.
Reconstitution math
Concentration is everything: the same 600 mg vial gives a different draw for every amount of bacteriostatic water you add. The table uses the common 3 mL setup for each vial size, which puts every unit on a U-100 insulin syringe at 2 mg for the default vial. Dashes mark draws too small to measure or larger than the syringe.
| Vial | BAC water | Concentration | 200 mg | 400 mg | 600 mg |
|---|---|---|---|---|---|
| 200 mg | 3 mL | 66.6667 mg/mL | - | - | - |
| 600 mg | 3 mL | 200 mg/mL | 100 u | - | - |
| 1,200 mg | 3 mL | 400 mg/mL | 50 u | 100 u | - |
Dosing and protocol
Common antioxidant protocol: 200 to 600 mg, a few times weekly.
Doses of 200 to 600 mg are drawn in large volumes compared to peptides: at 200 mg/mL (a 600 mg vial in 3 mL), a 400 mg dose is a 2 mL injection. Oxidation is the practical enemy; reconstituted glutathione degrades faster than most compounds on this page, so small vials used quickly beat big vials stored long.
Pharmacokinetics
No curve is shown, on purpose.
Intravenous studies show glutathione clears plasma in minutes, and there is little rigorous data for the subcutaneous route. Plan by total weekly dose; a concentration curve has nothing honest to say here.
How it is thought to work
A tripeptide of glutamate, cysteine and glycine, and the body's principal intracellular antioxidant and phase II detoxification substrate. It is synthesized in cells, which is what makes supplementing it complicated.
What the evidence supports
This table grades how well each outcome has been studied in humans, not how well Glutathione works. A strong grade means the question was asked properly, and the answer may still have been negative. Nothing here is inherited from a drug class, a close analog, or the parent molecule of a fragment.
| Outcome | Strongest published evidence |
|---|---|
| Oral supplementation raising body stores | Human RCT |
| Oxidative stress markers | Human RCT |
| Skin lightening | Human, observational |
| Safety of intravenous cosmetic use | No data |
Storage and handling
Lyophilized vials keep best cold, dark, and dry; refrigeration is the community default and freezing lyophilized powder is common for long holds. After reconstitution, refrigerate at 2 to 8 C, do not freeze the solution, and date the vial. Bacteriostatic water's preservative keeps multi-dose use practical for about 28 days by USP convention, though our 120-day stability study found the preservative itself outlasts that window.
Got a certificate of analysis with your vial? Run it through our COA Reader: it reads the report in plain English, checks purity and mass against the label claim, and links the testing lab’s own verification page. Our guide to reading a COA explains what the numbers do and do not tell you.
Sources
- Richie et al., Randomized controlled trial of oral glutathione supplementation, Eur J Nutr 2015PMID 24791752 · DOI
- Allen and Bradley, Effects of oral glutathione on biomarkers of oxidative stress, J Altern Complement Med 2011