Sensory quality: strongly aromatic.

The content of essential oil varies drastically with climate, time of harvest and storage conditions; extreme values are 0.75% and 6.5%. Main components are the phenols thymol (ca. 40%) and carvacrol (ca. 15%). In winter, phenol content is lower (but mostly thymol); in summer, more phenols (up to 70%) are found, with significant amounts of carvacrol. Further components in the essential oil are thymol methyl ether (2%), cineol, cymene, a-pinene, borneol and esters of the latter two.
Thymus citriodorus contains an essential oil rich in geraniol (up to 60%); other compounds identified include geranyl esters, nerol and citronellol. The lemon fragrance is due to citral (14%), and thymol was found in small (0.5%) yet not insignificant amounts.

Thyme contains essential oils including thymol which is a strong antiseptic that is gentle on the skin. In addition to being antiseptic Thyme is known to be an expectorant, antispasmodic and carminative. Thyme has been used to treat gastrointestinal problems, respiratory disorders and against hookworm. European herbalists have long used it for relaxing baths or in compresses and gargles. It is reportedly beneficial in treating the headache from a hangover and toothache.