Epigallocatechin Gallate

Epigallocatechin gallate (EGCG) is a green-tea polyphenol used primarily as an antioxidant/anti-inflammatory in leave-on products, typically around ~0.05–1%. Clinical and consumer-use data suggest it is generally well tolerated, but polyphenols can still provoke stinging or dermatitis in a minority of highly reactive or eczematous patients (especially in alcohol-heavy or low-pH formulas). Given its overall favorable tolerability yet non-zero risk of irritation/sensitization in compromised skin, it fits best as a gentle (but not inert) ingredient. Safety Notes: In commercial skincare, EGCG is most often delivered via green tea extracts where the effective EGCG contribution can be very low; at the low end, products that list EGCG as a minor antioxidant/soothing adjunct commonly use ~0.001–0.01% in leave-on serums/creams (and similarly low levels in rinse-off cleansers due to short contact time). Higher-strength consumer-available antioxidant serums and targeted post-sun/anti-redness formulations using more purified EGCG or standardized green-tea actives are observed up to about 0.5–1%, with concentrations above this being uncommon due to stability (oxidation), color/odor, and irritation/sensory constraints. There is no specific FDA/EU maximum for EGCG in cosmetics, so the practical upper end is driven primarily by formulation feasibility and tolerability rather than regulation.