Thymol
Thymol is a phenolic compound found in thyme oil, ajowan seeds (also called ajwain or carom), and horsemint. It is an isomer of carvacrol, meaning it has the same molecular formula but the atoms are arranged differently. Thyme is widely used as an antibacterial, an antimicrobial and an antifungal. It is a very effective disinfectant, being even better than carbolic acid. According to the EPA it is also used in perfumes, food flavorings, mouth wash (Listerine) and cosmetics. Some over the counter medications use thymol for acne, hemorrhoids and athletes foot. It is an ingredient of Vicks Vaporub, which has given many people relief from foot fungus.
Thymol was registered for use as a pesticide in the United States in 1964, to be used for repelling domestic animals. It is also listed by the Food and Drug Administration as a food additive, on the GRAS (Generally recognized as Safe) list. According to an EPA Fact Sheet, they are not aware of any adverse effects of thymol on humans or the environment, and haven't had any significant reports of incidents with thymol.
A 2006 study showed that thymol inhibited the ability of E.coli and Staphylococcus aureus to adhere to human cells. Thymol also has a antimicrobial mechanism whereby it disrupts the bacterial cell wall and causes the contents or cytoplasm, to leak out. According to a study published in Pharmacology in 2006, thymol also has antioxidant and anti-inflammatory properties in humans. It is used to treat hookworms and other parasites.
Thymol is an effective natural way to fight a type of mite called Varroa that attacks honey bees. Thymol is lethal to the mites, but doesn't affect the bees or humans. Studies have found that there are residues left in the beeswax from this treatment, but much less in the honey itself. Also, this compound tends to break down very quickly, so the residues don't really get worse over time. The only concern is that the thymol residues change the taste of the honey.
Ancient Egyptians used thymol and carvacrol, derived from the thyme plant, as part of their preparation to preserve mummies. You can see it would be ideally suited for this with all of its abilities to kill fungus and microbes. Thymol has also been used in book binding, to kill spores in books that need rebinding after mold damage.
Thymol is produced synthetically today and can be found in many topical ointments and oils formulated for joint massage, nail fungus, etc. As for taking thymol supplements, it's not clear whether this would be safe for humans. According to the ScienceLab Material Safety Data Sheet, thymol is a skin and eye irritant and toxic to mucous membranes. Unless you can vouch for the safety of a supplement, I recommend eating lots of thyme from your garden and lots of Indian food with ajowan seeds as a safe way to get thymol into your diet.
The information on this page is not meant to be used in treatment of medical conditions. Please seek the advice of a physician about any medical condition or symptom. Those with medical conditions should consult a medical professional about the appropriateness of taking dietary supplements or diet therapy, and how these methods will interact with their medications.
Phytochemical Society of North America
Phytochemical Society of Europe
For detailed information about the chemical structure, formula, and molecular weight of various phytonutrients, visit
The US Dept of Agriculture.
Phytochemicals also gives detailed information on specific phytochemicals.
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