Glutathione Oxidized (GSSG) (CAS 27025-41-8) is supplied by TCS NEXUS S.L. (Valencia, Spain) for European cosmetic formulators, brand R&D teams and B2B buyers reviewing cosmetic antioxidant active applications. A freely water-soluble active, it dissolves directly in aqueous concentrates without co-solvents at pH 4.5–7.5, with cool-down addition below 40°C recommended in standard serum and leave-on manufacturing protocols.
> Technical Specifications
| Product Name | Glutathione Oxidized (GSSG) |
|---|---|
| Molecular Structure |  |
| CAS Number | 27025-41-8 |
| Alias / Common Name | GSSG; Oxidized glutathione; Glutathione disulfide; L-Glutathione oxidized |
| Molecular Formula | C20H32N6O12S2 |
| Molecular Weight | 612.60 g/mol |
| INCI Name | Glutathione Oxidized |
| Functional Class | Oxidized glutathione (disulfide form); melanogenesis pathway modulator; GSSG/GSH redox signalling active; brightening active |
| Purity / Assay | ≥98% (HPLC); confirm by batch COA |
| Appearance | White to off-white powder |
| Solubility / Handling | Freely water-soluble; dissolve in deionised water or aqueous phase; stable in oxidised form — no nitrogen blanket required |
| pH Stability | Optimal stability at pH 4.5–7.5; stable in the oxidised disulfide form under normal atmospheric conditions |
| Storage | Store sealed below −20°C in the dark; more stable than reduced GSH under atmospheric conditions; follow batch COA and SDS |
> Mechanism & Positioning
Glutathione Oxidized (GSSG, CAS 27025-41-8) is the disulfide-linked oxidised form of glutathione (γ-Glu-Cys-S-S-Cys-γGlu dimer), representing the oxidised half of the glutathione redox couple (GSH/GSSG) that regulates cellular redox homeostasis. Published GSSG literature discusses the melanogenesis pathway modulation through the GSSG/GSH redox ratio: a shift in the intracellular GSSG:GSH ratio towards oxidative status promotes melanin synthesis by activating MITF nuclear translocation and downstream tyrosinase, TRP-1 and DCT enzyme upregulation, while a reducing GSH-dominant environment attenuates melanin production. Cell-based melanocyte studies document GSSG-stimulated melanin pathway activity alongside GSH-mediated melanin suppression — establishing the redox-switching rationale. Brightening model data also notes direct interaction of GSSG with dopachrome-tautomerase (DCT/TRP-2) active site elements, providing a secondary anti-melanogenic pathway distinct from the primary GSH mechanism, and supporting GSSG use as a complementary active to reduced glutathione in brightening serum formulation concepts.
Based on available in vitro data, Glutathione Oxidized (GSSG) is positioned for brightening serum, redox-modulation skin-care concentrate and advanced melanogenesis-pathway formulation concepts. The GSSG form is more stable in atmospheric oxygen than reduced GSH — requiring no nitrogen blanket during formulation. For comprehensive glutathione-family brightening positioning, GSSG may be evaluated alongside reduced Glutathione (GSH) for dual-form redox-based melanin pathway modulation, and with brightening peptides such as Hexapeptide-2 for MC1R/tyrosinase pathway complementation.
> Application Concepts
Brightening Serum: GSSG Redox Pathway Architecture
Glutathione Oxidized (GSSG) dissolves freely in deionised water and aqueous serum bases at 0.05–0.5% (w/w) without co-solvent and without nitrogen blanketing requirements — unlike reduced GSH, the disulfide GSSG form is stable under atmospheric oxygen. Introduce during the cool-down phase below 40°C. Formulate at pH 4.5–7.5 compatible with brightening serum bases. For a comprehensive glutathione-redox brightening system, combine GSSG (0.05–0.2%) with reduced GSH (0.1–0.5%) to establish a controlled GSH/GSSG ratio in the serum, alongside niacinamide (3–5%) for melanosome transfer inhibition and vitamin C (5–15%) for tyrosinase inhibition. Confirm combined stability and GSSG/GSH assay retention by HPLC after accelerated testing.
Formulation Stability Advantages of GSSG vs GSH
The oxidised GSSG form offers significant formulation stability advantages over reduced Glutathione (GSH). Reduced GSH contains a free thiol (—SH) group that is susceptible to atmospheric oxidation, metal-catalysed oxidation and disulfide-bond formation — requiring nitrogen blanketing, antioxidant co-actives and airless packaging. GSSG, as the already-oxidised disulfide, is stable under normal atmospheric conditions without special oxygen-exclusion handling, making it significantly easier to incorporate in standard emulsion and serum manufacturing. At 0.05–0.5% in aqueous serum, GSSG can be added to the warm or cool-down phase without a nitrogen environment. Compare Glutathione GSH for the reduced form and its brightening mechanism when a reducing-dominant GSH signal is the formulation target.
Melanogenesis Redox Modulation and Multi-Active Brightening
In brightening serum concepts targeting multiple melanogenesis pathways, GSSG contributes a redox-signalling mechanism — shifting the intracellular GSH/GSSG ratio — that is independent from and complementary to tyrosinase-enzyme inhibitors (kojic acid, vitamin C, azelaic acid) and MSH receptor modulators (Hexapeptide-2). Building a thorough brightening serum with GSSG + niacinamide + a tyrosinase inhibitor + an MSH pathway modulator provides four-point melanogenesis coverage across the GSSG/GSH redox switch, melanosome transfer, tyrosinase enzyme activity and MC1R/MITF signalling. At 0.05–0.5% GSSG, all combinations are water-soluble and pH-compatible at 5.0–7.0. Confirm combined stability before scale-up.
> Handling & Formulation Notes
Dissolve Glutathione Oxidized (GSSG) in deionised water or the aqueous phase at ambient temperature at 0.05–0.5% (w/w). Unlike reduced GSH, no nitrogen blanketing or oxygen-exclusion conditions are required — GSSG is stable in atmospheric oxygen as the already-oxidised disulfide form. Introduce during the cool-down phase below 40°C. Maintain pH within 4.5–7.5.
Evaluate compatibility with reducing agents (sodium ascorbate, thioglycolate, DTT) that may convert GSSG back to GSH — this may or may not be desired depending on formulation intent. Confirm GSSG assay retention by HPLC after accelerated stability testing at 40°C/75% RH. Standard preservative systems and packaging are compatible; airless packaging is not required for GSSG (unlike for reduced GSH).
> Supply & Documentation
Glutathione Oxidized (GSSG) (CAS 27025-41-8) is available from TCS NEXUS S.L. (Valencia, Spain) for B2B cosmetic raw material projects. Standard documentation: COA, TDS, SDS. Sample and bulk quantities are discussed on a per-project basis; contact info@tcspeptides.com to initiate a sourcing review.
TCS NEXUS S.L. supports procurement and formulation teams in Germany, France, Italy, Spain, the United Kingdom, the Netherlands, Belgium, Poland, Sweden and Portugal, as well as international buyers in the United States, Canada, Japan, South Korea, Australia and New Zealand.
> Packaging & Storage
Glutathione Oxidized (GSSG) is supplied in sealed aluminium foil bags or bulk containers. Minimum quantities and packaging configurations are confirmed per order. Store sealed at −20°C in the dark, protected from moisture. Once reconstituted, store at −20°C in single-use aliquots. Confirm batch-specific storage conditions in the SDS and COA.
> FAQ
What is Glutathione Oxidized (GSSG)?
Glutathione Oxidized (GSSG) (CAS 27025-41-8) is a cosmetic raw material supplied by TCS NEXUS S.L. (Valencia, Spain) for B2B cosmetic formulators. It is positioned for melanogenesis-modulating brightening serum, stable antioxidant replenishment and skin redox-balance concepts at 0.05–1.0%.
What is the CAS number for Glutathione Oxidized (GSSG)?
The CAS number for Glutathione Oxidized (GSSG) is 27025-41-8. The INCI name for cosmetic regulatory documentation and CPNP notification is Glutathione Oxidized; confirm CAS 27025-41-8 and INCI identity against the batch COA when building product files.
How does GSSG support even tone — and how does it relate to reduced GSH?
Glutathione Oxidized (GSSG) is the disulfide-linked dimer of two glutathione molecules — the oxidised partner of reduced glutathione (GSH) in the cellular GSH/GSSG redox couple. In brightening positioning GSSG is described as modulating the melanogenesis pathway and, via the redox couple, influencing tyrosinase-related pigment control; some formulators prefer it because the disulfide form is more stable to handle than the readily-oxidising reduced GSH.
What use level of GSSG is typical, and how should it be evaluated?
Because the effective level shifts with formulation and claim, build it up conservatively from your own evaluation instead of fixing on one number. We supply pure GSSG with COA; contact info@tcspeptides.com to align documentation.
Which actives pair with GSSG in a brightening formula?
GSSG combines with tyrosinase-focused brighteners such as alpha-arbutin, kojic acid and vitamin C, with niacinamide, and with the reduced form Glutathione (GSH) where a redox-balanced system is wanted. Keep the base mildly acidic and confirm combined stability and colour in the finished formula.
What is the difference between GSSG and reduced glutathione (GSH)?
Reduced glutathione (GSH) is the active thiol antioxidant that readily oxidises in air; Glutathione Oxidized (GSSG) is the disulfide dimer that forms once GSH has given up its reducing power. GSSG is the more stable, easier-to-handle form and is used for redox-signalling and brightening positioning. This raw material is GSSG (CAS 27025-41-8); TCS NEXUS S.L. also supplies reduced Glutathione (GSH) separately — confirm which form your formulation needs. GSSG is freely water-soluble.
What addition temperature is recommended for Glutathione Oxidized (GSSG) during manufacturing?
Introduce Glutathione Oxidized (GSSG) during the cool-down phase at temperatures below 40°C; avoid prolonged exposure above this threshold. Standard aqueous or emulsion cool-down protocols are fully compatible with this addition requirement. Confirm thermal stability in the specific manufacturing process with accelerated stability data before committing to production scale.
What pH range keeps GSSG stable in a finished formula?
Glutathione Oxidized is most stable under mildly acidic conditions, around pH 4.0–6.5, and is more robust than the reduced form; still avoid strongly alkaline systems and confirm the finished-product pH after all actives are incorporated.
Is Glutathione Oxidized (GSSG) compatible with other actives in multi-active cosmetic systems?
Glutathione Oxidized (GSSG) is compatible with standard cosmetic actives at pH 4.5–7.5 in aqueous or emulsion systems. Evaluate combined system pH drift, clarity and assay retention; confirm preservative compatibility. Run accelerated stability testing at 40°C/75% RH before scale-up.
Is Glutathione Oxidized (INCI) compliant with EU Cosmetics Regulation 1223/2009?
Glutathione Oxidized is not listed as a restricted, prohibited or regulated substance under EU Cosmetics Regulation 1223/2009 Annexes II–VI. The finished product manufacturer is responsible for the CPSR and CPNP notification. Use CAS 27025-41-8 and INCI name Glutathione Oxidized consistently in all regulatory documentation; confirm purity and identity against the batch COA.
How should Glutathione Oxidized (GSSG) be stored?
Store Glutathione Oxidized (GSSG) sealed at −20°C in the dark, protected from moisture and air. Once opened, reseal immediately. Once opened, reseal the container immediately. Follow specific storage and handling conditions stated in the SDS and batch COA. Confirm shelf life for the specific batch before incorporating into production formulations.
What documentation does TCS NEXUS S.L. provide for Glutathione Oxidized (GSSG)?
TCS NEXUS S.L. provides COA (confirming CAS 27025-41-8 and HPLC purity ≥98% (HPLC)), TDS (Technical Data Sheet) and SDS (Safety Data Sheet) for Glutathione Oxidized (GSSG). Additional documentation such as specification sheets and INCI confirmation letters is available on a per-project basis. Contact info@tcspeptides.com to initiate a documentation and sourcing discussion.
What MOQ and sample options are available for Glutathione Oxidized (GSSG)?
Sample and bulk quantities for Glutathione Oxidized (GSSG) are confirmed on a per-project basis through TCS NEXUS S.L. Minimum order quantities depend on current stock, packaging configuration and project scope. R&D teams are encouraged to request samples for stability and concentration-range evaluation before bulk planning. Contact info@tcspeptides.com with project specification to begin a sourcing review.
> Technical Support and Samples
Request COA documents, sample availability, or support for custom synthesis.