Arctium Lappa Root Extract

Arctium lappa (burdock) root extract is a botanical skin-conditioning/soothing ingredient typically used at low concentrations (often <1–2%), and it is generally well tolerated in standard cosmetic patch-test experience. However, as a plant extract it contains multiple bioactive constituents and has a non-trivial risk of irritant reactions or allergic contact dermatitis in highly reactive or eczema-prone patients, especially in compromised skin barriers or leave-on routines. Given the variability in extract composition and the sensitive-skin safety priority, a mild (0.4) irritancy score is the most clinically cautious match. Safety Notes: In mass-market leave-on toners/serums and many rinse-off shampoos/cleansers, Arctium Lappa (Burdock) Root Extract is commonly used as a label-claim botanical at very low levels (often ~0.0005–0.1% active extract, especially when supplied as a dilute glycerin/propylene glycol extract). Higher concentrations are found in “botanical-heavy” acne/oily-scalp products, masks, and herbal scalp tonics where the extract is a primary functional component, reaching ~1–5% in OTC consumer formulas depending on the extract’s solvent system and solids content. This range reflects real commercial practice for both leave-on and rinse-off products; above ~5% is uncommon due to cost, odor/color impact, and stability/sensory constraints rather than regulatory limits.