Polygonum Tinctorium Leaf Extract

Polygonum tinctorium (indigo plant) leaf extract is typically used at low concentrations as an antioxidant/soothing botanical, and it is generally well-tolerated in leave-on products. However, like many plant extracts it contains multiple bioactive constituents with variability between batches, and there are documented cases of botanical extracts provoking irritant or allergic contact dermatitis in reactive or eczema-prone patients. Given the non-zero sensitization potential despite common “calming” positioning, I rate it as gentle but not exceptionally gentle. Safety Notes: In commercial skincare, Polygonum Tinctorium (indigo plant) leaf extract is most often used as a low-level soothing/antioxidant botanical, commonly appearing in leave-on serums, creams, and toners at trace-to-low levels (~0.0005–0.1%) typical of supplier-recommended use rates for plant extracts. Higher-strength consumer-available products (especially “Cica/soothing” ampoules, concentrated essence/serum formats, and some botanical gels) have been observed formulating it around ~0.5–3% when the extract is a featured hero ingredient; above this is uncommon due to cost, color/odor, stability, and sensory constraints. Rinse-off cleansers typically sit toward the low end because of short contact time, while leave-on products span the full range.