Glutathione
Master Antioxidant | Tripeptide | GSH
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What is Glutathione?
Glutathione is a naturally occurring three-amino-acid peptide made by nearly every cell in the body, often called the body's main antioxidant. Researchers study injectable glutathione because it bypasses the digestive system's poor absorption of the oral form, and published research has looked at its role in cellular antioxidant activity, detoxification pathways, and neurological research models. It's sold here strictly as a research chemical for laboratory study, not for use in people or animals.
Key terms:
Glutathione is a tripeptide.
Glutathione (GSH) is a tripeptide — three amino acids: glutamate, cysteine, and glycine. It is often called the body's 'master antioxidant.' It is found in virtually every cell. Its critical roles include neutralizing free radicals, detoxifying harmful substances, recycling other antioxidants (vitamins C and E), and supporting immune function. Glutathione levels decline with age. Stress, toxins, and certain diseases deplete them further. Injectable forms bypass poor oral bioavailability — how little survives digestion — and deliver glutathione directly to tissues.
Key research areas
- Direct delivery bypasses poor oral bioavailability
- Rapidly increases plasma glutathione levels
- Supports detoxification, immune function, and antioxidant defense systems
Researched dosing
This table reflects dosing schedules used in research and clinical-study settings for glutathione — presented as research-methodology reference, not usage instructions.
| Phase | Dose | Frequency | Route |
|---|---|---|---|
| General antioxidant studies | 200-400 mg | 1-2x weekly | IM or IV push |
| Detoxification studies | 400-600 mg | 2-3x weekly | IV push or slow infusion |
| Immune-function studies | 400-600 mg | 1-2x weekly | IV or IM |
| Neurological studies (Parkinson's) | 1400 mg | 3x weekly | IV infusion (clinical protocol) |
| Maintenance | 200 mg | 1x weekly | IM or SubQ |
Commonly cycled 8 weeks on, 4+ weeks off.
How it works
At the cell level, glutathione research looks at how its sulfur-containing chemical group neutralizes reactive molecules (free radicals) and helps recycle other antioxidants — the terms below describe those same chemical reactions.
Glutathione directly neutralizes reactive oxygen species via its sulfhydryl group, conjugates toxins for excretion (Phase II detoxification), recycles vitamins C and E, and supports optimal lymphocyte function. The tripeptide's unique gamma peptide bond protects it from degradation by most peptidases.
Molecular data
These figures — molecular weight, chain length, sequence — are the chemistry ID researchers use to confirm a glutathione sample's identity; at three amino acids, it's one of the smallest peptides made naturally in the body.
- Weight
- 307.33 Da
- Length
- 3 amino acids
- Type
- Tripeptide
Glutamate-Cysteine-Glycine
Pharmacokinetics
This chart shows how quickly a research dose of glutathione clears from the bloodstream in cited studies — notice the very short timescale, which is why researchers look at repeated dosing rather than single doses.
- Peak
- 0.233 hr
- Half-life
- 0.233 hrs
- Cleared
- ~1 hrs
Aebi et al. - High-dose IV Glutathione Pharmacokinetics
Research applications
This section summarizes the research areas — antioxidant activity, detoxification pathways, immune function, and neurological research — that scientists have studied for glutathione, a summary of what's been investigated in the literature, not medical claims about people.
Antioxidant Support
Glutathione is the body's primary intracellular antioxidant. Its sulfhydryl group donates electrons to neutralize free radicals and reactive oxygen species before they damage cells. Regenerates oxidized vitamins C and E back to their active forms, extending their protective capacity through the glutathione-ascorbate cycle. Maintains optimal GSH/GSSG ratio (typically >100:1 in healthy cells), a key indicator of cellular health and oxidative stress status.
Detoxification
Conjugates toxins for excretion via Phase II detoxification pathway, supporting liver function and overall detoxification processes.
Immune Function
Supports optimal lymphocyte function and immune resilience through antioxidant defense mechanisms.
Neurological Health
GSH levels are reduced by 40% in the substantia nigra of Parkinson's patients. Intranasal glutathione has shown potential for increasing brain GSH levels and mild motor improvement in Parkinson's patients.
Skin Health
Potential improvements in skin appearance with consistent use over time. Skin lightening effects, if any, are modest and temporary, requiring ongoing treatment to maintain.
Dosage reference
- Doses used in research
- 200–600 mg per dose
- Frequency in studies
- 1-3x per week
- Handling
- Reconstituted solution — research use only; not for administration
- Timeline reported in studies
- Plasma levels peak rapidly with IV (minutes). Cellular effects build over weeks of consistent use. Full benefits typically assessed after 4-8 week cycles.
- Storage
- Refrigerate at 2-8°C (36-46°F). Protect from light. Do not freeze. Use within manufacturer's expiration date.
- Cycle length
- 4-8 weeks typical
- Break between cycles
- 4 weeks off after 4-8 weeks on is commonly recommended, though some protocols allow ongoing use
Reconstitution & storage
This describes how a research-grade glutathione sample is prepared and stored — most research formulations come pre-mixed, and this is a chemistry-handling note, not a usage guide.
- Most glutathione injections come pre-mixed - no reconstitution required
- If lyophilized: reconstitute with sterile water or bacteriostatic water per manufacturer instructions
- Inspect solution - should be clear and colorless to slightly yellow
- Store the reconstituted solution refrigerated (2–8°C), labeled with the date and concentration, for laboratory research use only.
Lyophilized: 2-8°C, use within Per manufacturer expiration date
Reconstituted: 2-8°C, use within Per manufacturer expiration date
Quality indicators
These are the checks — sourcing, labeling, formulation pH, stability — researchers and buyers look at to confirm a glutathione sample is correctly identified and hasn't degraded.
Licensed Compounding Pharmacy - Obtain from accredited compounding pharmacy (PCAB accreditation preferred) with proper sterility testing and quality controls.
Proper Form (Reduced GSH) - Ensure product contains reduced glutathione (GSH), not oxidized glutathione (GSSG), which must be converted by the body.
Clear Labeling - Product should clearly list concentration (e.g., 200mg/mL), lot number, expiration date, and proper storage requirements.
Healthcare Provider Supervision - IV administration should be performed by or under supervision of licensed healthcare provider who can manage potential adverse reactions.
pH Affects Comfort - Improperly buffered glutathione causes significant injection site stinging/pain. Quality formulations should be pH-adjusted to 6.0-7.0, close to physiological pH.
Short Half-Life - Plasma glutathione has a short half-life (~14 minutes). Benefits come from repeated administration and supporting endogenous production, not single doses.
Variable Bioavailability - Even with injection, cellular uptake varies. Some tissues take up glutathione better than others. Brain uptake is limited without intranasal route.
Unregulated Sources - Avoid products from non-licensed sources. Contamination, incorrect concentration, and degraded product are significant risks.
What to expect
This timeline summarizes what the research literature reports at each study stage — research context for comparing studies, not a personal-results promise.
Minimal noticeable effects. Plasma glutathione levels increase acutely after each injection but have short half-life (~14 minutes for reduced GSH).
Some may notice improved energy or recovery. Detoxification processes are supported. Individual responses vary significantly.
Potential improvements in skin appearance, immune resilience, or neurological symptoms depending on indication. Effects are often subtle.
Safety notes
This section covers handling cautions and regulatory notes for glutathione — research-use-only scope, not medical advice.
- DO NOT use during chemotherapy without oncologist approval - may interfere with treatment
- Avoid during pregnancy and breastfeeding - safety not established
- Individuals with G6PD deficiency may be at risk for hemolysis with high doses
- May worsen asthma symptoms in susceptible individuals - avoid inhaled forms
- Requires prescription from licensed healthcare provider
- Philippine FDA has issued warnings about IV glutathione for cosmetic skin lightening
Regulatory status
- Not approved by the FDA for any indication.
- Supplied and described for laboratory research use only — not for human or veterinary use.
Community data
Community Insights
Based on data the community reported. Not clinical proof.
Frequently asked questions
What is glutathione studied for in research?
Glutathione (GSH) is a naturally occurring tripeptide of glutamate, cysteine, and glycine — often called the "master antioxidant." Research examines its roles in neutralizing reactive oxygen species, Phase-II detoxification, and recycling vitamins C and E. Injectable research forms bypass poor oral bioavailability. It is supplied as a research-use-only reference material.
How is glutathione reconstituted or prepared for laboratory use?
Many research glutathione preparations arrive pre-mixed and need no reconstitution. If lyophilized, sterile or bacteriostatic water is added per the supplier’s instructions and swirled until dissolved. The solution should look clear and colorless to slightly yellow; anything cloudy or discolored is discarded. It is then labeled and refrigerated.
How should glutathione be stored?
Glutathione is kept refrigerated at 2-8°C and protected from light, since the molecule oxidizes readily. A shift from near-colorless to deeper yellow can signal oxidation. Cold, dark storage preserves the reduced (active) form for the research period, and solutions with particles or heavy discoloration are discarded.
What purity should a glutathione COA show?
A research-grade Certificate of Analysis should confirm identity and report purity by HPLC — commonly at or above 98% — ideally distinguishing reduced (GSH) from oxidized (GSSG) forms, with mass-spec confirmation of the roughly 307 Da molecular weight. Third-party testing and a clear solution provide additional quality assurance against the COA.
References
Classic pharmacokinetic study demonstrating that IV glutathione significantly increases plasma levels but has a short half-life (~14 minutes), with rapid conversion to cysteine and other metabolites.
Landmark study showing GSH levels were reduced by 40% in the substantia nigra of Parkinson's patients compared to controls, establishing the oxidative stress connection in PD pathogenesis.
Double-blind, placebo-controlled trial found intranasal glutathione increased brain GSH levels and showed mild motor improvement in Parkinson's patients, though placebo group also improved.