Grifola Frondosa Fruiting Body Extract

Grifola frondosa (maitake) fruiting body extract is typically used at low concentrations as a soothing/antioxidant, polysaccharide-rich botanical with generally good tolerability in leave-on products. However, as a complex fungal-derived extract it contains multiple bioactive fractions and can still trigger irritation or rare allergic reactions in highly reactive or eczema-prone patients, especially when the extract is less purified. Given this sensitization uncertainty despite low intrinsic irritancy, it fits best as a generally gentle ingredient rather than “very gentle.” Safety Notes: In commercial skincare, Grifola frondosa (maitake) fruiting body extract is most often used as a minor supportive botanical in multi-extract serums/creams/toners at very low levels (around 0.001–0.1%), consistent with typical supplier use-rates for standardized mushroom extracts and INCI placements near the end of lists. Higher-strength consumer products marketed around “mushroom/maitake” benefits (leave-on essences/ampoules/creams) and some mask formats can reach ~1–5% when the formula is built around the extract and tolerability/stability allows. Rinse-off cleansers typically sit toward the low end due to brief contact time and cost, while leave-on treatments span the full range.