Glutathione (GSH) is a tripeptide antioxidant (MW 307.32 Da) supplied as a lyophilized powder for research. Because it oxidizes readily, sourcing quality and proper storage matter more for glutathione than for many peptides.
What to Look for When Sourcing Glutathione
Require a third-party COA confirming ≥98% purity and the correct 307.32 Da molecular weight. Reduced (GSH) versus oxidized (GSSG) form matters for research — verify which form is supplied, and prefer sealed vials protected from air and light.
Typical Price Range
Research-grade glutathione typically costs around $35–$55 per vial. Because it is inexpensive to synthesize, unusually cheap material more often reflects the oxidized or degraded form than a bargain.
Storage and Handling
Store lyophilized glutathione at 2–8°C, protected from light and moisture. Reconstituted glutathione oxidizes quickly and should be used promptly and kept refrigerated — this is a key difference from more stable peptides.
Red Flags to Avoid
Avoid vendors with no COA, no indication of reduced vs oxidized form, purity claims without documentation, or human-use claims. Rapid oxidation makes freshness and proper storage especially important for glutathione.
Top Recommended Source
Purgo Labs is our top-rated source based on third-party COA verification, research-grade purity, and transparent manufacturing. View at Purgo Labs.