Body & Beauty / Compounds / Costus root oil

Costus root oil on your skin: a safety profile

High risk

(People-specific data is limited; this page draws from human adult context.) Strong sensitizer — contains costunolide and dehydrocostus lactone (sesquiterpene lactones); IFRA prohibited in consumer products since 2002 due to extreme sensitization potency

What is costus root oil?

Also known as: Costus oil.

CAS number
8023-88-9

Risk for people

High risk

Strong sensitizer — contains costunolide and dehydrocostus lactone (sesquiterpene lactones); IFRA prohibited in consumer products since 2002 due to extreme sensitization potency

Regulatory consensus

2 regulatory and scientific bodies have classified Costus root oil. The classifications differ — that's the data.

AgencyYearClassificationNotes
IFRA2004prohibitionIFRA prohibited — extreme sensitizer
EU_COSMETICS2009bannedEU Annex II — prohibited

Regulators apply different standards of evidence — animal-data weighting, exposure-pattern assumptions, epidemiological power thresholds — which is why two scientific bodies can review the same data and reach different conclusions. The disagreement is the data.

Where you encounter costus root oil

  • Personal Care — perfume (restricted)
  • Fragrance — perfume, cologne, scented personal care products, household fragrance products, candles
    Identified in Fragrance Ingredient Safety Priority Research database (2,325 ingredients)

Safer alternatives

Lower-risk approaches that achieve a similar outcome to Costus root oil:

  • Synthetic costus lactone (purified)
    Trade-offs: Alternative fragrance ingredient; individual safety profile should be assessed per IFRA standards; sensitization potential varies by compound; patch testing recommended for sensitive individuals.
    Relative cost: 1.2-2×
  • Agarwood accords
    Trade-offs: Alternative fragrance ingredient; individual safety profile should be assessed per IFRA standards; sensitization potential varies by compound; patch testing recommended for sensitive individuals.
    Relative cost: 1.2-2×

Frequently asked questions

What products contain costus root oil?

Costus root oil appears in: perfume (restricted) (Personal care); perfume (Fragrance); cologne (Fragrance).

See Costus root oil in the body app

Look up products containing costus root oil, compare to alternatives, and explore the full data record.

Open in body View raw API data

Sources (1)
  1. PubChem Compound Database (2026) — database

Reference data, not professional advice. Aggregates publicly available regulatory and scientific data; not a substitute for veterinary, medical, legal, or regulatory advice. Why we built ALETHEIA →