Glutathione (GSH) (CAS 70-18-8) is supplied by TCS NEXUS S.L. (Valencia, Spain) for European cosmetic formulators, brand R&D teams and B2B buyers reviewing cosmetic peptide raw material applications. A freely water-soluble peptide, it dissolves directly in aqueous concentrates without co-solvents at pH 4.5–6.5, with cool-down addition below 40°C recommended in standard serum and leave-on manufacturing protocols.
> Technical Specifications
| Product Name | Glutathione (GSH) |
|---|---|
| Molecular Structure |  |
| CAS Number | 70-18-8 |
| Alias / Common Name | GSH; Reduced glutathione; L-Glutathione reduced; gamma-L-Glutamyl-L-cysteinylglycine |
| Molecular Formula | C10H17N3O6S |
| Molecular Weight | 307.33 g/mol |
| INCI Name | Glutathione |
| Functional Class | Tripeptide antioxidant; cellular reducing agent; GPx/GR enzyme substrate; anti-melanogenic active |
| Purity / Assay | ≥98% (HPLC); confirm by batch COA |
| Appearance | White to off-white hygroscopic powder |
| Solubility / Handling | Freely water-soluble; dissolve in deionised water at ambient temperature; nitrogen-blanket or low-oxygen dissolution recommended to minimise oxidation |
| pH Stability | Optimal stability at pH 4.0–7.0 in aqueous systems; most stable under slightly acidic conditions (pH 4.5–6.0); avoid alkaline pH above 8.0 |
| Storage | Store sealed below −20°C under inert atmosphere (nitrogen or argon) to prevent oxidation; hygroscopic — reseal immediately; follow batch COA and SDS for specific conditions |
> Mechanism & Positioning
Glutathione (GSH, CAS 70-18-8) is the endogenous γ-Glu-Cys-Gly tripeptide that functions as the primary intracellular reducing agent in skin cells, operating as the main substrate for glutathione peroxidase (GPx) and glutathione S-transferase (GST) enzyme systems responsible for peroxide detoxification and electrophile conjugation. Published Glutathione literature discusses ROS scavenging — primarily hydrogen peroxide (H₂O₂) and lipid hydroperoxide — via GPx-catalysed reduction, generating oxidised glutathione (GSSG), which is recycled to GSH by glutathione reductase (GR) in a NADPH-dependent cycle. Cell-based keratinocyte and melanocyte studies document anti-melanogenic activity associated with GSH-driven tyrosinase pathway modulation: reduced GSH shifts melanin synthesis towards the pheomelanin (lighter pigment) route, attenuating eumelanin production in melanocyte assay systems under oxidative challenge. Brightening model data also notes the role of GSH in protecting melanocytes and keratinocytes against UV-induced oxidative DNA damage and lipid peroxidation, providing a dual antioxidant–brightening mechanistic rationale in cosmetic positioning.
Based on available in vitro data, Glutathione (GSH) is positioned for brightening serum, antioxidant concentrate, UV-after-care and oxidative-stress-protection formulation concepts. The free reduced GSH form has limited stability in oxidising formulation environments — combine with antioxidant system (vitamin C, vitamin E) and pH control at 4.5–6.5 to preserve activity. For complementary antioxidant positioning, GSH combines with Ergothioneine (TAUT-transported superantioxidant) and Ectoin (extremolyte barrier stabilisation) for multi-mechanism antioxidant serum architecture.
> Application Concepts
Brightening Serum and Antioxidant Concentrate Architecture
Glutathione (GSH) dissolves freely in deionised water or glycerin–water at 0.05–2.0% (w/w) for brightening serum, vitamin C synergy concentrate or antioxidant toner applications. Dissolve under nitrogen or low-oxygen conditions to minimise pre-formulation oxidation of the thiol group. Introduce during the cool-down phase below 40°C in an oxygen-limited environment; consider nitrogen sparging of the batch during cool-down. Formulate at pH 4.5–6.5 for optimal GSH stability; avoid alkaline pH above 7.0. Package in airless pump or nitrogen-flushed tube format to limit post-manufacture oxidative exposure. Confirm residual GSH content via HPLC after forced oxidation studies (40°C/75% RH, 6 weeks) before finalising the antioxidant system design.
Brightening Mechanism and Anti-Melanogenic Serum Design
The anti-melanogenic positioning of Glutathione in brightening serums rests on its role in the melanin synthesis pathway switch. In melanocytes under oxidative stress or after UV exposure, GSH competes with the melanin biosynthesis cascade at the DOPA-quinone reactive intermediate stage, favouring pheomelanin (yellow-red, lighter pigment) formation over eumelanin (brown-black). At GSH concentrations of 0.05–2.0% in the formulation, sufficient GSH must reach the melanocyte — penetration enhancement (glycol, ethosome, liposome delivery) may support bioavailability. Combine with vitamin C (L-ascorbic acid at 5–15%) for tyrosinase inhibition and GSH regeneration support; combine with niacinamide for melanosome transfer inhibition. Confirm combined pH stability (typically pH 3.0–4.0 for ascorbic acid vs pH 4.5–6.5 for GSH) before scale-up.
UV-After-Care and Oxidative Stress Protection Formulations
Glutathione’s role in GPx-mediated peroxide detoxification and DNA oxidative damage repair makes it relevant for UV-after-care lotion, post-procedure concentrate and environmental pollution shield formulations. At 0.05–2.0% in an emulsion or serum base, GSH provides free radical scavenging alongside antioxidant enzyme-system substrate replenishment — a different mechanism from lipid-soluble antioxidants (vitamin E, ferulic acid) operating in the membrane phase. Combine with Ergothioneine and L-Carnosine for three-mechanism aqueous antioxidant architecture covering GPx-pathway (GSH), TAUT-transported intracellular defence (Ergothioneine) and metal-chelation/anti-glycation (Carnosine). Package in nitrogen-flushed airless format for maximum stability.
> Handling & Formulation Notes
Dissolve Glutathione (GSH) in deionised water or the aqueous phase under nitrogen or low-oxygen conditions at 0.05–2.0% (w/w) at ambient temperature. The free thiol (—SH) group is sensitive to oxidation by atmospheric oxygen — work quickly, use nitrogen-sparged water and introduce into the formulation during a nitrogen-blanketed cool-down phase below 40°C. Maintain pH within 4.5–6.5; avoid alkaline pH above 7.0, which accelerates thiol oxidation.
Do not combine with strong oxidising agents, high concentrations of transition metals (iron, copper) without chelation, or prolonged exposure to air at elevated temperatures. Package in airless or nitrogen-flushed containers. Confirm residual GSH content by HPLC after stability protocols before committing to production batches. For formulations where oxidation stability is challenging, consider Glutathione Oxidized (GSSG) as a complementary brightening active with distinct chemistry.
> Supply & Documentation
Glutathione (GSH) (CAS 70-18-8) 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 (GSH) is supplied in sealed aluminium foil bags or bulk containers, nitrogen-flushed where available. Minimum quantities and packaging configurations are confirmed per order. Store below 25°C in a cool, dry, low-oxygen environment. The free thiol (—SH) group is sensitive to atmospheric oxidation — store in sealed containers and minimise air exposure on opening. Follow batch COA and SDS for specific storage and handling conditions.
> FAQ
What is Glutathione (GSH)?
Glutathione (GSH) (CAS 70-18-8) is a cosmetic raw material supplied by TCS NEXUS S.L. (Valencia, Spain) for B2B cosmetic formulators. It is positioned for brightening serum, antioxidant concentrate, UV-after-care and oxidative-stress-protection formulation concepts where GPx-pathway ROS scavenging and melanin synthesis modulation are the claim directions.
What is the CAS number for Glutathione (GSH)?
The CAS number for Glutathione (GSH) is 70-18-8. The INCI name for cosmetic regulatory documentation and CPNP notification is Glutathione; confirm CAS 70-18-8 and INCI identity against the batch COA when building product files.
How does Glutathione brighten skin and act as an antioxidant?
Glutathione (GSH) is the tripeptide γ-Glu-Cys-Gly and the skin’s principal thiol antioxidant. In brightening positioning it is described as inhibiting tyrosinase and shifting melanin synthesis away from darker eumelanin toward lighter pheomelanin, while its reducing thiol group quenches the reactive oxygen species involved in melanogenesis. This combined antioxidant and even-tone action is its cosmetic rationale.
What use level of Glutathione is typical, and does the pure-peptide basis matter?
The appropriate dose is formulation- and claim-dependent, so build it up conservatively from your own evaluation instead of fixing on one published number. We supply pure reduced Glutathione with COA so you can dose on a pure-material basis and, importantly, track the reduced-GSH content over shelf life. Contact info@tcspeptides.com to align documentation with your target and stability plan.
Which actives pair with Glutathione in a brightening formula?
Glutathione is frequently paired with vitamin C (ascorbic acid), which supports even-tone results and helps keep GSH in its active reduced form, and with niacinamide, alpha-arbutin or tranexamic acid in a brightening stack. Because GSH prefers slightly acidic, low-oxygen conditions, confirm that co-actives fit that window and verify combined stability and colour in the finished base.
Why does GSH oxidise, and how do you keep it stable in a formula?
The cysteine thiol (-SH) in glutathione readily oxidises to the disulfide-linked GSSG dimer on exposure to air, metal ions or alkaline pH, which lowers the level of active reduced GSH. To protect it, dissolve under a nitrogen blanket or low-oxygen conditions, hold the formula slightly acidic (about pH 4.5–6.0), consider a chelator plus a compatible antioxidant, and use airless or low-headspace packaging. Confirm reduced-GSH assay retention across the intended shelf life.
How should Glutathione be dissolved and added during manufacturing?
Glutathione is freely water-soluble and hygroscopic — weigh it quickly and dissolve it in deionised water at ambient temperature, ideally under nitrogen or reduced-oxygen conditions to limit oxidation. Add it during the cool-down phase and keep processing temperatures low, since both excessive heat and prolonged air exposure accelerate conversion to GSSG.
What pH keeps Glutathione most stable?
Reduced glutathione is most stable under slightly acidic conditions, around pH 4.5–6.0, and should be kept below pH 8.0, since alkaline systems markedly accelerate its oxidation. This slightly-acidic preference makes it a natural fit alongside low-pH actives such as vitamin C. Confirm the finished-product pH and reduced-GSH content after all actives are incorporated.
What is the difference between reduced GSH and oxidised glutathione (GSSG)?
Reduced glutathione (GSH) is the active antioxidant form used for brightening and free-radical positioning; oxidised glutathione (GSSG) is the disulfide dimer that forms once GSH gives up its reducing power. This raw material is the reduced GSH form (CAS 70-18-8). TCS NEXUS S.L. also supplies Glutathione Oxidized (GSSG) as a separate material — confirm which form and CAS your formulation needs against the batch COA.
Is Glutathione (INCI) compliant with EU Cosmetics Regulation 1223/2009?
Glutathione 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 70-18-8 and INCI name Glutathione consistently in all regulatory documentation; confirm purity and identity against the batch COA.
How should Glutathione (GSH) be stored?
Store Glutathione (GSH) sealed below 25°C in a cool, dry location protected from direct light and moisture. 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 (GSH)?
TCS NEXUS S.L. provides COA (confirming CAS 70-18-8 and HPLC purity ≥98% (HPLC)), TDS (Technical Data Sheet) and SDS (Safety Data Sheet) for Glutathione (GSH). 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 (GSH)?
Sample and bulk quantities for Glutathione (GSH) 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.