Body & Beauty / Compounds / Thymol

Thymol on your skin: a safety profile

Low risk

(People-specific data is limited; this page draws from human adult context.) Natural phenol from thyme; antimicrobial; used in mouthwash (Listerine active ingredient); GRAS; low toxicity

What is thymol?

The IUPAC name is 5-methyl-2-propan-2-ylphenol.

Also known as: 5-methyl-2-propan-2-ylphenol, 2-Isopropyl-5-methylphenol, Thyme camphor, 5-Methyl-2-(1-methylethyl)phenol.

IUPAC name
5-methyl-2-propan-2-ylphenol
CAS number
89-83-8
Molecular formula
C10H14O
Molecular weight
150.22 g/mol
SMILES
CC1=CC(=C(C=C1)C(C)C)O
PubChem CID
6989

Risk for people

Low risk

Natural phenol from thyme; antimicrobial; used in mouthwash (Listerine active ingredient); GRAS; low toxicity

Regulatory consensus

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

AgencyYearClassificationNotes
FDA1965GRASGRAS food flavoring — thyme component
US_EPA2024registered_antimicrobialEPA-registered antimicrobial ingredient (biopesticide)

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 thymol

  • Personal Care — essential oils, oral care, antiseptics
  • Food — spice flavoring (thymol, carvacrol)
  • 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 Thymol:

  • Menthol (for oral care)
    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×
  • Cetylpyridinium chloride (mouthwash)
    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 thymol?

Thymol appears in: essential oils (Personal care); oral care (Personal care); spice flavoring (thymol, carvacrol) (Food); perfume (Fragrance); cologne (Fragrance).

See Thymol in the body app

Look up products containing thymol, 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 →