Researched by Helena DeMaria-Williams
Formula IngredientAntioxidantEUK-134 (Ethylbisiminomethylguaiacol Manganese Chloride)
INCI: Ethylbisiminomethylguaiacol Manganese Chloride
Ethylbisiminomethylguaiacol Manganese Chloride (commonly known as EUK-134) is a synthetic, manganese-based molecule that mimics the activity of two natural skin enzymes: superoxide dismutase (SOD) and catalase. Unlike typical antioxidants that neutralise a single free radical, EUK-134 operates catalytically — it converts superoxide radicals into hydrogen peroxide and then breaks that hydrogen peroxide down into harmless water and oxygen. This dual-action cycle allows a small concentration to provide ongoing protection against oxidative stress.
Category
Antioxidant
Irritation Risk
Low
Skin Types
all skin types, sensitive skin, redness-prone skin, mature skin, UV-damaged skin
What does this do in a formula?
antioxidant protection, neutralises free radicals, reduces UVB-induced oxidative damage, lowers hydroperoxide levels on UVA-exposed skin, reduces facial redness and erythema, protects skin cell DNA from UV-related damage
Is EUK-134 (Ethylbisiminomethylguaiacol Manganese Chloride) safe? Key considerations
Can EUK-134 (Ethylbisiminomethylguaiacol Manganese Chloride) cause irritation?
Low RiskWell-tolerated in clinical studies, including by sensitive and redness-prone skin types. No significant irritation has been reported in peer-reviewed literature. No EU CosIng Annex II or III restrictions apply to this ingredient. Patch testing is still advisable for highly reactive skin, as data on this ingredient is more limited than for widely-used antioxidants such as vitamin C.
Does EUK-134 (Ethylbisiminomethylguaiacol Manganese Chloride) increase sun sensitivity?
No RiskEUK-134 does not increase photosensitivity. On the contrary, it actively protects against UV-induced oxidative damage by scavenging free radicals generated by UVA and UVB exposure. It is not an exfoliant or retinoid and does not thin the stratum corneum. Standard daily SPF use is always recommended, but EUK-134 itself does not require additional sun protection precautions.
Is EUK-134 (Ethylbisiminomethylguaiacol Manganese Chloride) safe during pregnancy?
MANUAL REVIEW: No specific pregnancy safety data identified across reviewed sources. Not classed as hazardous in general use, but no MotherToBaby or EWG pregnancy guidance found for this ingredient.No specific guidance on EUK-134 safety during pregnancy has been identified from EWG Skin Deep, MotherToBaby, or INCIDecoder. It is a synthetic manganese complex; systemic absorption from topical use at 0.1% is expected to be negligible. However, due to the absence of dedicated pregnancy safety assessments, use with caution and consult a healthcare provider.
How does EUK-134 (Ethylbisiminomethylguaiacol Manganese Chloride) work?
Ethylbisiminomethylguaiacol Manganese Chloride (commonly known as EUK-134) is a synthetic, manganese-based molecule that mimics the activity of two natural skin enzymes: superoxide dismutase (SOD) and catalase. Unlike typical antioxidants that neutralise a single free radical, EUK-134 operates catalytically — it converts superoxide radicals into hydrogen peroxide and then breaks that hydrogen peroxide down into harmless water and oxygen. This dual-action cycle allows a small concentration to provide ongoing protection against oxidative stress.
Which products contain EUK-134 (Ethylbisiminomethylguaiacol Manganese Chloride)?
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