Fraxinus Excelsior Bark Extract

Fraxinus excelsior (ash) bark extract is a botanical antioxidant/soothing extract used at low concentrations, but as a complex mixture (including phenolics/coumarin-like constituents) it carries a non-trivial risk of stinging or dermatitis in highly reactive or eczematous skin compared with inert humectants. Clinical patch-test data for this specific extract is limited and plant extracts show variable composition, so I score it as mild: generally tolerated, but occasional sensitivity can occur, especially when combined with other actives or on compromised barriers. Safety Notes: Fraxinus excelsior (ash) bark extract is typically used as a minor botanical active/soothing or anti-fatigue component in leave-on skincare, often appearing near the end of INCI lists at trace-to-low levels (~0.001–0.1%) in mass-market creams, toners, and eye products. In more “active botanical” or spa-style serums/creams, total ash bark extract can be formulated at higher levels (commonly ~0.5–2%), with the upper end (~3–5%) seen in consumer-available high-botanical-content leave-on products where the extract is a key claim ingredient; rinse-off products generally stay at the lower end due to brief contact time.