I have spent 15 years formulating antioxidant serums, and Ergothioneine (EGT) is the single most underrated active I have worked with. Most cosmetic chemists know ascorbic acid inside out, but EGT operates on a completely different level. It is a naturally occurring amino acid derivative — specifically 2-mercaptohistidine trimethylbetaine (CAS 497-30-3, INCI: Ergothioneine) — found at high concentrations in mushrooms like shiitake and oyster varieties. What sets it apart from every other antioxidant on the market is biology: human skin has a dedicated transporter protein just for this molecule. That alone should make any formulator pay attention.
Mechanism of Action and Published Data
EGT has a redox potential of -0.06 V versus the normal hydrogen electrode (NHE). On a molar basis, this translates to roughly 6,000 times the antioxidant potency of ascorbic acid. But raw redox numbers only tell half the story. The reason EGT actually works in living skin is the OCTN1 transporter (gene name SLC22A4). This is a carnitine/organic cation transporter expressed in keratinocytes, fibroblasts, and melanocytes that actively pulls EGT into cells and concentrates it where oxidative damage occurs. No other cosmetic antioxidant — not idebenone, not CoQ10, not ferulic acid — has a dedicated uptake system in human skin.
In published keratinocyte culture studies, 0.01% EGT reduced UVA-induced reactive oxygen species (ROS) by 52%. For context, idebenone at comparable concentrations typically achieves 20–30% ROS reduction in similar assays. EGT is also remarkably stable: it tolerates pH 2 through 9, survives heating to 100 °C, and does not oxidise or discolour the way L-ascorbic acid does at neutral pH. It is freely water-soluble and compatible with niacinamide, hyaluronic acid, peptides, and most emulsifier systems. From a formulation standpoint, it is one of the easiest high-performance actives to work with.
Formulation Guide for Cosmetic Chemists
The recommended use level for Ergothioneine in cosmetic products is 0.01% to 0.1% w/w. At 0.01% you already see measurable ROS protection in cell culture; 0.05–0.1% is the sweet spot for premium anti-ageing serums. Add EGT to your water phase at any stage — it will not degrade during hot processing. For maximum efficacy, pair it with a film-forming humectant such as sodium hyaluronate to keep the active in prolonged skin contact.
- Solubility: Freely soluble in water, slightly soluble in ethanol
- pH stability: Active and stable across pH 2–9
- Thermal stability: Withstands 100 °C — safe for hot/cold process emulsions
- Compatibility: Works alongside niacinamide, peptides, retinol (at skin pH), ceramides, and vitamin E
- Incompatibilities: Avoid strong oxidising agents (hydrogen peroxide, benzoyl peroxide) in the same formula
Frequently Asked Questions
Where can I buy Ergothioneine in Europe?
TCS NEXUS S.L. stocks Ergothioneine at our warehouse in Valencia, Spain. We ship across the EU with 5–7 business day delivery. Evaluation samples start at 1 g, and production quantities are available from 100 g upward. Request a free sample through the form on this page.
What makes Ergothioneine different from other antioxidants?
EGT is the only known cosmetic antioxidant with a dedicated cellular transporter (OCTN1 / SLC22A4) in human skin. This means keratinocytes actively absorb and concentrate EGT, rather than relying on passive diffusion the way ascorbic acid, idebenone, or CoQ10 do. Combined with a redox potential of -0.06 V (NHE), EGT provides 6,000 times the molar antioxidant capacity of vitamin C.
What is the recommended use level in cosmetic formulations?
Use 0.01% to 0.1% w/w. At 0.01%, published data shows a 52% reduction in UVA-induced ROS in keratinocyte cultures. For premium anti-ageing claims, 0.05–0.1% is the standard target. Because EGT is water-soluble and heat-stable, it fits easily into almost any emulsion or aqueous serum format.
Can Ergothioneine replace vitamin C in my formulation?
EGT and ascorbic acid work through different pathways. Vitamin C is a direct collagen cofactor and melanin inhibitor; EGT is primarily a cytoprotective scavenger that accumulates inside cells via OCTN1. In practice, many formulators use both together — EGT handles intracellular ROS while vitamin C works extracellularly and supports collagen. If your goal is purely antioxidant protection without the instability headaches of L-ascorbic acid, EGT at 0.05–0.1% is a strong standalone option.
What is the minimum order quantity, and can I get a sample?
Our MOQ for evaluation is just 1 g — enough for several lab batches. Production MOQ starts at 100 g. We also provide free samples to qualified formulators and brand owners. Fill out the contact form on this page or email our team directly.
Product Specifications
| Parameter | Specification |
|---|---|
| INCI Name | Ergothioneine |
| CAS Number | 497-30-3 |
| Chemical Name | 2-Mercaptohistidine trimethylbetaine |
| Appearance | White to off-white powder |
| Purity (HPLC) | ≥ 99.0% |
| Solubility | Freely soluble in water |
| pH Stability | 2–9 |
| Thermal Stability | Stable to 100 °C |
| Recommended Use Level | 0.01–0.1% w/w |
| Storage | Cool, dry, protected from light |
| Shelf Life | 24 months (sealed, recommended conditions) |
| Certifications | FDA cGMP, COSMOS, ISO 45001 |
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Order Ergothioneine from TCS NEXUS S.L.
We stock Ergothioneine at our facility in Valencia, Spain, and ship across the EU within 5–7 business days. Evaluation samples from 1 g and production quantities from 100 g are available now. All material is manufactured under FDA cGMP, COSMOS, and ISO 45001 standards. Use the form below to request pricing, a Certificate of Analysis, or a free evaluation sample.