Arctium Lappa Root Extract
Also known as Burdock root extract, Greater burdock root extract, Gobo root extract
“No regulator has issued a verdict on this ingredient.”
Arctium Lappa Root Extract (burdock root, Asteraceae/Compositae family) is NOT covered by any published CIR safety assessment. The September 2022 CIR Quick Reference Table lists only 'Arctium Lappa Seed Oil' (Finding=S, IJT 36(Suppl. 3):51-129, 2017 — the Plant-Derived Fatty Acid Oils group report, which covers seed-derived oils, not root extracts). Direct searches of the CIR ingredient database surface no Arctium Lappa Root assessment as of April 2026. The packet is therefore PubMed-only; the readiness gate (which requires cir + cosing) will refuse to score this ingredient until CIR coverage exists, and that refusal is the correct system response. Available evidence base: a 2024 pharmacological review (PMID 39162715) identifies arctiin, arctigenin (lignans), inulin, chlorogenic acid, and polyacetylenes as principal root constituents; a 2011 pharmacology review (PMID 20981575) explicitly documents 'contact dermatitis and other allergic/inflammatory responses' as a known adverse-effect risk; a 1995 case report (PMID 8549139) documents allergic contact dermatitis attributable directly to burdock. Asteraceae cross-reactivity is biologically plausible (sesquiterpene-lactone class allergens documented broadly across Compositae per PMID 12492516), but PMID 12492516 itself does NOT name Arctium among its enumerated Compositae sensitizers — the cross-reactivity claim is class-level inference, not ingredient-specific evidence.
Active root constituents: lignans (arctiin and its aglycone arctigenin — documented anti-inflammatory and antioxidant activity), inulin (fructo-oligosaccharide, prebiotic and humectant properties), polyacetylenes, chlorogenic acid, and other polyphenols (per PMID 39162715, 2024 review).
Marketed cosmetic claims: anti-inflammatory and skin-soothing for oily/acne-prone and irritated skin; the 2011 pharmacology review notes traditional use 'to improve skin quality and texture' and topical eczema applications.
Plant: Arctium lappa L. (Asteraceae/Compositae family, Asterales order, Arctium genus per PMID 39162715). The root-derived extract is biochemically distinct from the seed oil (CIR-assessed Safe under the 2017 Plant-Derived Fatty Acid Oils group report) and from the fruit/seed extract (separate INCIs not covered here). Cosmetic-grade root extract typically derives from first-year roots harvested before the plant flowers.
NO CIR ASSESSMENT exists for Arctium Lappa Root Extract. The September 2022 CIR Quick Reference Table contains only 'Arctium Lappa Seed Oil' (a different INCI, covered by the 2017 Plant-Derived Fatty Acid Oils group report, which is scoped to oil preparations and does NOT extend to root extracts). The readiness gate requires CIR coverage; this ingredient cannot be scored as VERIFIED_SAFE or GENERALLY_SAFE on current evidence. Plant-part discipline: Seed Oil and Root Extract are different INCIs and different CIR scopes — the seed oil verdict cannot be transferred.
Direct allergic contact dermatitis to burdock (Arctium lappa) is documented (PMID 8549139, 1995 case report; PMID 20981575, 2011 review explicitly listing 'contact dermatitis and other allergic/inflammatory responses' as a known side effect). Patch testing with Arctium lappa extract directly is needed to diagnose burdock-specific sensitization.
Asteraceae/Compositae family cross-reactivity is biologically plausible: Arctium lappa is in the Asteraceae family (Asterales order, Arctium genus per PMID 39162715), the same family as ragweed, arnica, calendula, chamomile, feverfew, and other documented Compositae sensitizers. Sesquiterpene lactones are the principal class allergens (per PMID 12492516, which reviewed 15+ Compositae sensitizing species but did NOT explicitly name Arctium among them — the cross-reactivity inference is class-level, not ingredient-specific). Individuals with documented Compositae-mix patch-test positivity should approach Arctium lappa products with caution.
Variable constituent profiles across extraction solvents (water, glycerin, propylene glycol, ethanol) and supercritical CO2 extracts; lignan (arctiin/arctigenin) and polyacetylene content — both with documented bioactivity and potential sensitization relevance — differ by preparation method and root maturity at harvest.
A 2011 review notes burdock root may also be associated with 'allergic/inflammatory responses' beyond contact dermatitis; the topical safety profile is less characterized than the oral/medicinal use profile, and most published evidence concerns oral or systemic exposure rather than cosmetic dosing.