Glutathione Quick Start
Glutathione is a tripeptide of glutamate, cysteine and glycine joined by an unusual gamma-linkage that protects it from ordinary peptidase breakdown. It is the dominant intracellular antioxidant and a substrate for detoxification enzymes. It differs from everything else in this catalog in that it is not a signalling molecule — it is consumed stoichiometrically in redox reactions, which is why the doses are measured in hundreds of milligrams rather than micrograms.
This guide is an educational research reference. It does not diagnose, treat, or prescribe, and is not medical advice. Consult a licensed clinician before considering any compound.
Glutathione Dosing Protocol
Glutathione doses are in the hundreds of milligrams — two to three orders of magnitude above the signalling peptides elsewhere on this site, because it is consumed in reactions rather than binding a receptor. Intravenous is the most-studied parenteral route; the subcutaneous and intramuscular figures below are research-planning references, not personal dosing recommendations.
Injection — Subcutaneous
| Band | Per dose | Frequency |
|---|---|---|
| Low | 200 mg | 1–3× weekly |
| Standard | 400 mg | 1–3× weekly |
| High | 600 mg | 1–3× weekly |
Glutathione Reconstitution Guide
Glutathione ships as a lyophilized powder that is markedly more oxidation-sensitive than the peptides elsewhere in this catalog. Reconstitute close to the time of use and keep the solution protected from air and light.
Injection
| BAC | Conc. | 400 mg |
|---|---|---|
| 3 mL | 500 mg/mL | 0.8 mL · 80 u |
| 5 mL | 300 mg/mL | 1.33 mL · 133 u |
Units are U-100 insulin-syringe units. At the higher bands a dose exceeds one 100-unit syringe — the 3 mL reconstitution keeps most doses within a single draw.
Oxidation, not degradation
The failure mode here is chemical conversion to GSSG rather than peptide breakdown. A discoloured or sulfurous-smelling solution should be discarded regardless of how recently it was mixed.
Reconstitution steps
- Inspect the vial. Confirm the label, expected milligram amount, and that the powder looks dry and intact.
- Wipe the stoppers. Use an alcohol swab on both the bacteriostatic water and peptide vial stoppers.
- Draw the chosen volume. 3 mL into the vial — this is the number that sets every concentration figure above.
- Inject down the wall. Release the water slowly down the inside wall, not directly onto the powder.
- Swirl, do not shake. Roll gently until dissolved. Shaking foams and can damage the peptide.
- Verify clarity. Solution should be clear and colorless. Any yellowing, cloudiness or sulfurous odour indicates oxidation — discard it.
- Label and refrigerate. Note the date and volume added on the vial, then store at 2–8 °C. Do not freeze the reconstituted solution.
See the bacteriostatic water guide for diluent handling, or the reconstitution calculator to work any other volume.
How Glutathione Works
Glutathione's active group is the cysteine thiol. It donates electrons to neutralise reactive oxygen species, becoming the oxidised dimer GSSG, which glutathione reductase then recycles back using NADPH. It is also the substrate glutathione S-transferases use to conjugate xenobiotics for excretion — the basis of its detoxification role. The gamma-linkage between glutamate and cysteine is what protects it from ordinary peptidases.
Thiol redox cycling
The cysteine sulfhydryl donates electrons; GSSG is recycled by glutathione reductase.
Phase II conjugation
Substrate for glutathione S-transferases in xenobiotic clearance.
Gamma-linkage
The unusual bond that resists standard peptidase degradation.
Open question
Whether parenteral glutathione meaningfully raises intracellular levels, where it actually works, is contested.
Who Should Avoid Glutathione
Glutathione is endogenous and generally low-risk, but parenteral administration of research-grade material is a different proposition from its physiological presence.
Asthma
Inhaled and parenteral glutathione have been associated with bronchoconstriction in asthmatic subjects.
Sulfur or thiol sensitivity
The active group is a thiol; sensitivity is a documented consideration.
Pregnancy & lactation
No established human safety data for supplemental parenteral use.
Concurrent chemotherapy
Antioxidants may interact with treatments that work through oxidative mechanisms — a clinician question.
Glutathione Side Effects & Safety
Generally low reported toxicity
Glutathione is endogenous and parenteral use has a relatively benign reported profile.
Bronchoconstriction in asthma
The most consistently flagged specific risk.
Injection-site reactions
Reported; inject slowly and rotate sites.
Oxidised product risk
Degraded material delivers GSSG rather than active GSH — a potency problem more than a toxicity one.
Glutathione Evidence Context
Established biochemistry
Glutathione's redox and conjugation roles are textbook cell biology and not in dispute.
Parenteral supplementation
Studied in Parkinson's disease and dermatological settings with modest and inconsistent results.
Bioavailability question
Whether exogenous glutathione raises intracellular levels is the central unresolved issue.
Open question
Precursor strategies such as NAC are sometimes argued to be more effective than glutathione itself.
Storage & Handling
| State | Storage | Notes |
|---|---|---|
| Lyophilized (powder) | −20 °C, desiccated, air- and light-protected | Oxidises readily — stricter than other items here. |
| Reconstituted (liquid) | 2–8 °C, use promptly | Not a multi-week solution; oxidation is the limiting factor. |
| Appearance | Clear, colorless | Yellowing or sulfurous odour indicates oxidation — discard. |
This is the most storage-sensitive item in the catalog on a chemical basis rather than a biological one. Oxygen exposure is the enemy, not time alone.
Frequently Asked Questions
Is glutathione a peptide?
Technically yes — a tripeptide — but it is not a signalling peptide. It is consumed stoichiometrically in redox reactions, which is why doses are hundreds of milligrams rather than micrograms.
How is it dosed?
Research-planning bands sit at 200–600 mg, one to three times weekly. At 500 mg/mL, 400 mg is 80 units on a U-100 syringe.
Why does it need such careful storage?
Reduced glutathione oxidises to GSSG on air contact, and GSSG is not the active species. Desiccated, air-protected storage and prompt use after reconstitution are requirements, not suggestions.
How do I know if it has oxidised?
Yellowing, cloudiness or a sulfurous odour. Discard rather than dose from it — the milligram figure on the label no longer reflects what is in solution.
Does injecting it raise cellular levels?
That is the central unresolved question. The biochemistry is established; whether exogenous glutathione reaches the intracellular compartment where it functions is contested, and some argue precursors like NAC are more effective.
Is this page medical advice?
No. It is an educational research reference and does not diagnose, treat, or prescribe. Consult a licensed clinician before considering any compound.
Glutathione Formats & Sourcing
Glutathione is supplied as a lyophilized powder in a single 1500 mg vial. There is no pre-reconstituted pen or spray format. Batch-specific Certificates of Analysis are issued per lot.
| Format | Supplied as |
|---|---|
| Vial | 1500 mg lyophilized powder |
Strengths are listed as sold; confirm against the product page and the batch COA before calculating anything.
Reference material for this protocol, with batch COA:
View Glutathione on Spyro Peptides →References
- Meister A, Anderson ME. Glutathione. Annu Rev Biochem (1983).
- Forman HJ, et al. Glutathione: overview of its protective roles, measurement, and biosynthesis. Mol Aspects Med (2009).
- Hauser RA, et al. Randomized, double-blind, pilot evaluation of intravenous glutathione in Parkinson's disease. Mov Disord (2009).
- Allen J, Bradley RD. Effects of oral glutathione supplementation on systemic oxidative stress biomarkers. J Altern Complement Med (2011).