Glutathione is a tripeptide (Glu-Cys-Gly, MW ~307.3 g/mol) and the most abundant intracellular antioxidant in mammalian cells. It is critical for Phase II detoxification, free radical scavenging, immune function, and cellular redox homeostasis. Injectable (SC/IV) glutathione bypasses the poor oral bioavailability (~3%) issue and achieves clinically meaningful plasma levels. It has been studied for conditions ranging from non-alcoholic fatty liver disease to Parkinson disease.
26 vendors tracked by PeptideAtlas list Glutathione, priced from $25.00 to $300. The lowest price per milligram is $0.017/mg at Mammoth Muscle Peptides (1500MG). 3 independent Janoshik purity tests cover Glutathione across 3 vendors. Results range from 98.6% to 99.9%.
Category: Antioxidant / Detoxification. Evidence rating: B (meaningful human data).
Clinical status: Widely used in clinical practice (IV/SC). Multiple Phase II/III trials for NAFLD, Parkinson disease, and cystic fibrosis.
Glutathione functions as the primary intracellular reducing agent, directly scavenging reactive oxygen species (ROS) and serving as a cofactor for glutathione peroxidase and glutathione-S-transferase enzymes. In its reduced form (GSH), it donates electrons to neutralize free radicals and…
Research base: 0 registered clinical trials and 20 indexed publications reference Glutathione.
Safety considerations: Generally well tolerated with injectable administration; Common: mild injection site discomfort, transient flushing with IV push; Rare: nausea, abdominal cramping, bloating.
Reviewed by the PeptideAtlas Editorial Team.
| Amino-acid sequence | Glu-Cys-Gly (gamma-linked) |
|---|---|
| Molecular formula | C10H17N3O6S |
| Molecular weight | ~307.3 g/mol |
| Half-life | ~1-2 hours (SC) |
| Bioavailability | ~100% SC; ~3% oral |
| Production method | synthetic |
| Anti-doping status | not-listed |
| US regulatory status | Available as dietary supplement (oral); injectable forms used in clinical practice but not FDA-approved as a drug. Compounding pharmacies provide SC/IV formulations. |
| Vendor | Size | Price | Price per mg |
|---|---|---|---|
| Mammoth Muscle Peptides | 1500MG | $25.00 | $0.017/mg |
| Archer Peptides | 1500MG | $30.00 | $0.020/mg |
| Great Lakes Peptides | 1500mg | $40.00 | $0.027/mg |
| PureRx Peptides | 1500mg | $42.00 | $0.028/mg |
| Petratide Science | 1500mg | $44.95 | $0.030/mg |
| All Peptides USA | 1500MG | $45.00 | $0.030/mg |
| US Peptide Co | 1500mg | $49.99 | $0.033/mg |
| Growth Guys | 1500mg | $50.00 | $0.033/mg |
| Great Northern Peptides | 1500mg | $55.00 | $0.037/mg |
| Peak Peptides | 1500mg | $60.00 | $0.040/mg |
| The Peptide Labs | 1500MG | $60.00 | $0.040/mg |
| Orbitrex Peptides | 1500mg | $69.99 | $0.047/mg |
| Purus Peptides | 1500MG | $70.00 | $0.047/mg |
| Red Fox Peptides | 1500mg | $70.00 | $0.047/mg |
| VitalCell Peptides | 1500 mg | $72.99 | $0.049/mg |
| Peplogix Peptides | 6000mg | $300 | $0.050/mg |
| RCGenix | 1500mg | $75.00 | $0.050/mg |
| Wholesale Peptide | 1500mg | $76.49 | $0.051/mg |
| AminoVault | 1500mg | $85.50 | $0.057/mg |
| Legendary Peptides | 600mg | $35.00 | $0.058/mg |
| Pacific Peptide | 1500mg | $120 | $0.080/mg |
| Bioscience Peptides | 1500MG | $129 | $0.086/mg |
| Lux Synth Aminos | 600mg | $55.00 | $0.092/mg |
| Charleston Peptide Supply | 600Mg | $64.99 | $0.108/mg |
| Arcane Peptides | 500MG | $65.00 | $0.130/mg |
| Vendor | Best tested purity |
|---|---|
| Penguin Peptides | 99.9% |
| Qing Li Peptide | 99.9% |
| UWA Elite Peptides | 98.6% |
Oral glutathione has extremely poor bioavailability (~3%) due to rapid degradation by GI peptidases and first-pass metabolism. SC injection achieves 100% bioavailability and clinically meaningful plasma levels. Liposomal oral forms are better than standard oral but still inferior to injection.
Yes, clinical evidence supports modest skin lightening through inhibition of tyrosinase and shifting melanin production toward lighter pheomelanin. This effect is dose- and duration-dependent and reversible upon discontinuation.
N-acetyl cysteine (NAC) is a precursor to glutathione — it provides cysteine, the rate-limiting amino acid for glutathione synthesis. NAC is orally bioavailable and raises intracellular glutathione levels over days to weeks. Direct glutathione injection provides immediate elevation but does not enter cells as efficiently as endogenously synthesized glutathione from NAC.
IV glutathione pushes are widely offered in wellness clinics but carry risks including anaphylaxis, Stevens-Johnson syndrome (rare case reports), and kidney toxicity at high doses. The FDA has not approved IV glutathione for any indication. SC injection at lower doses is generally better tolerated.
Vendors stocking it: Direct Peptides UK, Polar Peptides, Risynth Bio, Lux Synth Aminos, Reta-Peptide, Qianmiao Peptide, Zztai Peptide, All Peptides USA, Biomax Research, NovaPeptide, Mei Peptide, Pacific Peptide, Mammoth Muscle Peptides, Soma Chems, Wholesale Peptide, BleauGenics, Compound Purity, Purus Peptides, Peplogix Peptides, RCGenix, Petratide Science, Modern Peptides, Blue Line Research, Legendary Peptides, Amino Club, Rejuvenate Peptides, Charleston Peptide Supply, Treasure Coast Peptides, US Peptide Co, Bioscience Peptides, BioPure Peptides, Kitsune Compounds, Archer Peptides, Great Lakes Peptides, PureRx Peptides, VitalCell Peptides, Main Peptides, Catalyst Peptides, Peppertidez, NCRP Canada.
Coverage on this site: Common Cosmetic Peptides: Copper, Carnosine, Glutathione, and More, Five Enzyme Families That Build Short Oligopeptides and Peptide Drugs, Enzymatic Routes to Short Peptides: Mechanisms, Uses, Limits, Five Enzymatic Routes to Oligopeptides and Short Peptide Synthesis, Enzyme classes for biocatalytic synthesis of short oligopeptides, Enzymatic Routes to Oligopeptide Synthesis: A Technical Overview.