Aesculus hippocastanum Extract, commonly known as horse chestnut extract, is a botanical ingredient derived from the seeds, bark, or flowers of the Aesculus hippocastanum tree that is increasingly used in cosmetic science due to its anti‑inflammatory, antioxidant, and vascular‑supportive activities. Its bioactive components—primarily aescin (escin), saponins, flavonoids, and tannins—exhibit strong free‑radical scavenging capacity and anti‑edematous effects, which help reduce inflammation, soothe irritated skin, and protect against oxidative stress that contributes to premature aging and barrier compromise. Horse chestnut extract also displays astringent and vasoprotective properties, which can tighten the appearance of pores and support the resilience of the microvasculature in the skin, making it useful in formulations designed for sensitive, redness‑prone, or mature skin that benefits from enhanced tone and reduced puffiness. Its antioxidant profile has been shown to exhibit some of the highest active‑oxygen scavenging activity compared with diverse botanical extracts, reinforcing its utility in anti‑aging and protective skincare systems.

In haircare, Aesculus hippocastanum Extract may be incorporated into scalp and conditioning products to help support comfort, microcirculatory balance, and reduced irritation at the scalp level. Its anti‑inflammatory and antioxidant actions can help alleviate minor scalp inflammation and environmental stress, potentially contributing to stronger, healthier hair growth environments and reduced sensitivity. Additionally, its astringent components can assist in balancing excess sebum and supporting a refreshed scalp feel, which is beneficial in formulations such as shampoos, balms, and leave‑on scalp serums targeting oily or reactive scalps.