Ergothioneine
Natural amino acid synthesised by certain fungi and bacteria. In humans it accumulates in tissues via the specific OCTN1 transporter. In skin it acts as a strong antioxidant, scavenging hydroxyl radicals and protecting mitochondria and DNA. Used in premium antioxidant serums.
Evidence by route
Topical application
Antioxidant activity is well established in vitro. Topical clinical studies are limited: in vivo on healthy volunteers and in vitro on photodamage models. Clinically meaningful effects on photoageing or pigmentation versus vitamin C or niacinamide in head-to-head RCTs have not been demonstrated.
- Halliwell B et al. FEBS Lett. 2018;592(20):3357-3366. PMID 29851075
- Hseu YC et al. J Dermatol Sci. 2018;90(2):123-134. PMID 29395579
How to read tiers A–F
- BLimited evidence. One RCT or several controlled studies with limitations
Tolerability and safety
- Irritation potential
- Low
- Allergen risk
- Low
- Pregnancy
- Safe
- Suitable for
- Normal, Dry, Combination, Sensitive, Oily
About this ingredient
Ergothioneine (EGT) is a natural sulfur-containing amino acid. Only fungi and some bacteria synthesize it; humans and animals accumulate it from food via the specific OCTN1 transporter (SLC22A4). It concentrates in tissues with high oxidative stress: erythrocytes, liver, bone marrow, skin. Mechanism. Strong antioxidant with a unique profile: scavenges hydroxyl radicals, singlet oxygen, hypochlorite. Protects mitochondria and mitochondrial DNA from peroxidation. Unlike vitamin C, it does not switch to pro-oxidant in contact with iron and copper – important under inflammation and photodamage (Halliwell 2018). Where applied. Premium antioxidant serums and creams (0.1-2%). Brands include Estée Lauder Advanced Night Repair, SkinCeuticals, Japanese Mikimoto. In Spain found in Sesderma C-Vit and Endocare. Evidence base. In vitro and ex vivo studies on keratinocytes show protection from UVB-induced apoptosis and reduced inflammatory markers (IL-6, IL-8). Few clinical RCTs of topical ergothioneine exist as of 2024; no Cochrane or PubMed systematic review of topical use. The manufacturer Mibelle (TensUp) cites a 30-woman study showing wrinkle depth reduction over 12 weeks at 0.1%. Safety. CIR rated ergothioneine safe at cosmetic concentrations (2017). Non-irritating, non-comedogenic, does not photosensitize. Pregnancy – safe topically; lactation data are lacking, but systemic absorption is minimal. Suitable for sensitive and mature skin, post-procedure care, and photoaging.
Frequently asked questions
Is Ergothioneine safe during pregnancy?
Ergothioneine is considered safe during pregnancy at typical cosmetic concentrations. Systemic absorption through the skin is minimal.
What skin types is Ergothioneine for?
Ergothioneine suits: normal, dry, combination, sensitive, oily.
What is Ergothioneine and what does it do in cosmetics?
Natural amino acid synthesised by certain fungi and bacteria.
What's the INCI name for Ergothioneine?
The INCI name is Ergothioneine. It may also appear as: L-Ergothioneine, EGT.
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