What is it?
An essential oil steam-distilled from the leaves and flowering tops of common thyme, Thymus vulgaris. The thymol type, described in the European Pharmacopoeia, is about half thymol, a strongly aromatic compound, with p-cymene, gamma-terpinene, linalool and some carvacrol. In cosmetics it is used as an antimicrobial, antioxidant and preservative ingredient. Thyme and its oil also flavor foods, and thyme oil is used in traditional herbal cough and cold remedies.
Key information
- Thymol-type thyme oil is roughly half thymol.
- The European Food Safety Authority considers the undiluted oil irritating to skin and eyes and a skin and respiratory sensitizer.
- The EU herbal monograph on thyme oil advises against applying it to the face, especially around the nose, of babies and infants under 2.
- The EU's Scientific Committee on Consumer Safety found only limited evidence that thyme oil causes contact allergy.
More information
Thyme oil is distilled with steam from the fresh leaves, flowering tops and twigs, and the oil is then separated from the water. In 10 batches analyzed for the European Food Safety Authority (EFSA), thymol averaged about 50 percent, followed by p-cymene at about 18 percent, gamma-terpinene at about 9 percent and linalool at about 4 percent. Thyme leaves and their oil are added to a wide range of foods for flavor.
Concentrated, the oil is harsh. In 2025, EFSA concluded that thyme oil should be regarded as irritating to the skin and eyes and as a skin and respiratory sensitizer for people exposed to it. The European Medicines Agency’s monograph on thyme oil as a traditional herbal medicine allows skin preparations of up to 10 percent for adults, lists hypersensitivity reactions and skin irritation as possible side effects, and says it should not be applied to the face, particularly the nose area, of babies and infants under 2 because of the risk of a laryngospasm. It does not recommend skin use in anyone under 18, citing a lack of data.
Allergy to thyme oil appears uncommon. In its 2012 review of fragrance allergens, the EU’s Scientific Committee on Consumer Safety (SCCS) found only limited human evidence: in one study none of 200 patients reacted to thyme oil, and in another 4 of 86 patients already allergic to a standard fragrance mix did. The SCCS did not classify it as an established allergen.
On labels, look for Thymus Vulgaris Leaf Oil or Thymus Vulgaris Oil. The essential oil is meant to be diluted before it touches skin and kept away from the eyes. See also our Thyme Leaf Extract profile.
Sources: EFSA Journal (2025): Safety and efficacy of a feed additive consisting of thyme oil for all animal species; European Medicines Agency: EU herbal monograph on thyme oil (Thymus vulgaris L., Thymus zygis L., aetheroleum), 2020; SCCS: Opinion on fragrance allergens in cosmetic products (2012)
