Thyme (Thymus vulgaris L.), Thymol

Category

Herbs & Supplements

Synonyms

Common thyme, common garden thyme, English thyme, farigola, folia thymi, French thyme, garden thyme, Gartenthymian, herba thymi, herba timi, Labiatae (family), Lamiaceae (family), mother of thyme, red thyme, rubbed thyme, serpyllium, shepherd's thyme, Spanish thyme, ten, thick leaf thyme, time, timo, thym, thyme aetheroleum, thyme oil, thymi herba, Thymian, Thymus serpyllum, thymus zygis L., wild thyme, white thyme oil.

Note: There are up to 400 subspecies of thyme; common thyme (Thymus vulgaris) and Spanish thyme (Thymus zygis) are often used interchangeably for medicinal purposes. Not to be confused with calamint (calamintha ascendens, basil thyme) or with Spanish origanum oil (Thymus capitatus, Sicilian thyme, Spanish thyme).

Background

Thyme has been used medicinally for thousands of years. Beyond its common culinary application, it has been recommended for a myriad of indications, based upon proposed antimicrobial, antitussive, spasmolytic and antioxidant activity. To date, there are no well-defined controlled clinical trials to support thyme monotherapy for use in humans.

Thymol, one of the constituents of thyme, is contained in antiseptic mouthwashes, with limited clinical studies in the available literature to verify its efficacy as a monotherapy in dental outcomes, such as reductions in plaque formation, gingivitis and caries.

Traditional uses of thyme include for coughs and upper respiratory congestion; it continues to be one of the most commonly recommended herbs in Europe for these indications. The German Commission E (expert panel), has approved thyme for symptoms of bronchitis, whooping cough, and catarrh (inflammation of upper respiratory tract mucous membranes).

Experts have recommended the use of thymol in treatment of actinomycosis (lumpy jaw disease), onycholysis (separation or loosening of a fingernail or toenail from its nail bed), and paronychia (inflammation of the tissue surrounding a fingernail or toenail) due to its antifungal properties..

Evidence

DISCLAIMER: These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.

Alopecia areata (hair loss): There is currently insufficient information to recommend for or against the use of topical thyme oil for alopecia areata.
Grade: C

Bronchitis / cough: Thyme has traditionally been used for the treatment of respiratory conditions including cough and bronchitis. The German Commission E (expert panel), has approved thyme for use in bronchitis. However, due to a lack of available data evaluating thyme alone (and not in any combination products), additional study is needed to make a firm recommendation.
Grade: C

Dental plaque: One of thyme's main constituents, thymol, has antibacterial effects. Thymol is included as one of several ingredients in antiseptic mouthwashes such as Listerine®. Clinical studies have reported efficacy of Listerine® in decreasing plaque formation and gingivitis, although human evidence for thymol alone is limited.
Grade: C

Inflammatory skin disorders: Historically, thyme has been used topically for a number of dermatologic (skin) conditions. Results are mixed. Additional study is needed in this area.
Grade: C

Paronychia / onycholysis / antifungal: Thyme essential oil and thymol have antifungal effects. Topical thymol has been used traditionally in the treatment of paronychia (skin infection around a finger or toenail) and onycholysis (separation/loosening of the nail from the nail bed). Currently, there is insufficient evidence to recommend for or against thyme/thymol as a treatment for fungal infections.
Grade: C

Tradition

WARNING: DISCLAIMER: The below uses are based on tradition, scientific theories, or limited research. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider. There may be other proposed uses that are not listed below.
Abscess, acne, appetite stimulant, antioxidant, anxiety, arthritis, asthma, burns, cancer, cellulitis (skin inflammation), depression, gastritis (inflammation of the stomach), colic, cystitis (bladder infection), dermatitis, dermatomyositis (muscle inflammation), diarrhea, diuresis (increased urine production), dysmenorrhea (painful menstruation), dyspepsia (upset stomach), dyspnea (difficulty breathing), eczema, edema (swelling), enuresis (bed wetting), epilepsy, fever, flatulence (gas), flu, gingivitis, gout (foot inflammation), H. pylori, halitosis (bad breath), headache, heartburn, hookworms, indigestion, inflammation of the colon, insect bites, insomnia, intestinal parasites, laryngitis, lice, methicillin-resistant Staphylococcus aureus (MRSA), neuralgia (nerve pain), nightmares, obesity, pertussis (whooping cough), pruritis (severe itching), rheumatism, roundworms, scabies, scleroderma (chronic degenerative disease that affects the joints, skin, and internal organs), sinusitis, sore throat, spasms, sprains, stomach cramps, stomatitis (mouth sores), tonsillitis, urethritis, upper respiratory tract infection, urinary tract infection, vaginal irritation, warts, wound healing.

Dosing

Adults (18 years and older):

There is no proven safe or effective dose for thyme or thymol. Teas, liquid extracts, oils, ointments, compresses and combination products are all commercially available. Thyme oil is considered to be highly toxic and should not be taken internally. Combination products studied in available trials include Bronchipret® (Primulae radis and thyme) and Listerine® (containing thymol, a constituent of thyme).

For alopecia areata (hair loss), 2-3 drops of an essential oil combination (thyme, lavender, rosemary, and cedarwood added to grapeseed and jojoba oil) massaged into the scalp every night for seven months has been studied. For paronychia (skin infection around a finger or toenail), 1 drop of 1-2% thymol in chloroform to the affected area three times daily, or 1 drop of 4% thymol in chloroform to a chronically affected area three times daily has been used. Diluted thyme oil has been applied as needed in 1-2% ointments for a variety of skin disorders. Safety and efficacy have not been proven, and thyme oil is considered to be highly toxic.

As a compress for rheumatic diseases, bruises, and miscellaneous skin disorders, 5 grams of dried leaf per 100 milliliters boiling water for 10 minutes and strain has been used in compress form.

Children (younger than 18 years):

There is no proven safe or effective dose for thyme in children and use if not recommended. However, for prevention of periodontal infections, a combination product containing 1% chlorhexidine/thymol varnish (Cervitec®) was tolerated in 110 healthy children, ages 8-10 years old, when taken three times within two weeks.

Safety

DISCLAIMER: Many complementary techniques are practiced by healthcare professionals with formal training, in accordance with the standards of national organizations. However, this is not universally the case, and adverse effects are possible. Due to limited research, in some cases only limited safety information is available.

Allergies

Avoid in individuals with a known allergy or hypersensitivity to members of the Lamiaceae (mint) family or to any component of thyme, or to rosemary (Rosmarinus officinalis).

Cross-reactions to birch pollen, celery, oregano, and to other species in the Lamiaceae/Labiatae (mint) family may occur. Symptoms of allergy may include nausea, emesis (vomiting), pruritus (severe itching), angioedema (swelling under the skin), dysphagia (difficulty swallowing), dysphonia (altered voice), hypotension (low blood pressure), and progressive respiratory difficulty. Occupational asthma has been reported.

Side Effects and Warnings

Although not well studied in humans, thyme flowers and leaves appear to be safe in culinary and in limited medicinal use. Caution is warranted with the use of thyme oil, which should not be taken by mouth and should be diluted when applied on the skin due to potentially toxic effects.

Side effects of thyme taken by mouth may include headache, dizziness, hypotension (low blood pressure), bradycardia (slowed heart rate), heartburn, nausea, vomiting, diarrhea, gastrointestinal irritation, muscle weakness, and exacerbated inflammation associated with urinary tract infections. Use cautiously in patients with gastrointestinal irritation or peptic ulcer disease.

Taking thyme oil by mouth may also cause seizure, coma, cardiac arrest, or respiratory arrest. High doses of thyme or thyme oil may elicit tachypnea (rapid breathing). Inflammation of the eye and nasal mucosa has also been reported with exposure to thyme dust.

Topical application of Listerine® antiseptic solution to a chronic parenchyma of the toe has caused inflammation of the skin. Avoid topical preparations in areas of skin breakdown or injury, or in atopic patients. As an ingredient in toothpaste, cases of inflamed lips and tongue have been attributed to thyme oil.

Although not well studied in humans, Thymus serpyllum, a related species to Thymus vulgaris, has been shown to exert effects on the thyroid. Use cautiously in patients with thyroid disorders. Estradiol and progesterone receptor-binding activity has also been demonstrated.

Pregnancy and Breastfeeding

Thyme is not recommended in pregnant or breastfeeding women due to a lack of available scientific evidence. Thyme may act as an emmenagogue (promotes menstruation) and abortifacient (promotes abortion).

Interactions

Interactions with Drugs

Theoretically, thyme may decrease levels of thyroid hormone. Patients taking thyroid replacement therapy or anti-thyroid agents should use cautiously. Monitoring may be necessary.

Although not well studied in humans, thyme may interact with agents with estrogen or progesterone receptor activity. Examples of agents that may be affected include hormone replacement therapies and birth control pills.

Topical (applied on the skin) thymol may increase the absorption of 5-fluorouracil. Caution is advised in chemotherapy patients, as 5-fluorouracil is often used in cancer chemotherapy. Consult with a qualified healthcare professional, including a pharmacist, to check for interactions.

Interactions with Herbs and Dietary Supplements

Although not well studied in humans, thyme may interact with herbs with estrogen or progesterone receptor activity. Caution is advised when combining thyme with other herbs and supplements with proposed hormonal effects, such as black cohosh.

Attribution

This information is based on a systematic review of scientific literature, and was peer-reviewed and edited by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com): Ethan Basch, MD (Memorial Sloan-Kettering Cancer Center); Anja Bevens, PharmD (Northeastern University); Regina Gorenshteyn (Natural Standard Research Collaboration); Paul Hammerness, MD (Harvard Medical School); David Sollars, M.Ac, H.M.C. (New England School of Acupuncture); Shaina Tanguay-Colucci, BS (Natural Standard Research Collaboration); Catherine Ulbricht, PharmD (Massachusetts General Hospital); Wendy Weissner, BA (Natural Standard Research Collaboration).

Bibliography

DISCLAIMER: Natural Standard developed the above evidence-based information based on a thorough systematic review of the available scientific articles. For comprehensive information about alternative and complementary therapies on the professional level, go to www.naturalstandard.com. Selected references are listed below.

Armisen M, Rodriguez V, Vidal C. Photoaggravated allergic contact dermatitis due to Rosmarinus officinalis cross-reactive with Thymus vulgaris. Contact Dermatitis 2003;48(1):52-53.

Aschhoff B. Retrospective study of Ukrain treatment in 203 patients with advanced- stage tumors. Drugs Exp Clin Res 2000;26(5-6):249-252.

Baca P, Junco P, Bravo M, et al. Caries incidence in permanent first molars after discontinuation of a school-based chlorhexidine-thymol varnish program. Community Dent Oral Epidemiol 2003;31(3):179-183.

Baca P, Munoz MJ, Bravo M, et al. Effectiveness of chlorhexidine-thymol varnish for caries reduction in permanent first molars of 6-7-year-old children: 24-month clinical trial. Community Dent Oral Epidemiol 2002;30(5):363-368.

Charles CH, Sharma NC, Galustians HJ, et al. Comparative efficacy of an antiseptic mouthrinse and an antiplaque/antigingivitis dentifrice. A six-month clinical trial. J Am Dent Assoc 2001;132(5):670-675.

Dapkevicius A, van Beek TA, Lelyveld GP, et al. Isolation and structure elucidation of radical scavengers from Thymus vulgaris leaves. J Nat Prod 2002;65(6):892-896.

Fine DH, Furgang D, Barnett ML. Comparative antimicrobial activities of antiseptic mouthrinses against isogenic planktonic and biofilm forms of Actinobacillus actinomycetemcomitans. J Clin Periodontol 2001;28(7):697-700.

Haukali G, Poulsen S. Effect of a varnish containing chlorhexidine and thymol (Cervitec) on approximal caries in 13- to 16-year-old schoolchildren in a low caries area. Caries Res 2003;37(3):185-189.

Hay IC, Jamieson M, Ormerod AD. Randomized trial of aromatherapy. Successful treatment for alopecia areata. Arch Dermatol 1998;134(11):1349-1352.

Kelloway JS, Wyatt NN, Adlis S, et al. Does using a mouthwash instead of water improve the oropharyngeal removal of inhaled flovent (fluticasone propionate)? Allergy Asthma Proc 2001;22(6):367-371.

Knols G, Stal PC, Van Ree JW. Productive coughing complaints: Sirupus Thymi or Bromhexine? A double-blind randomized study. Huisarts en Wetenschap 1994;37:392-394.

Miura K, Kikuzaki H, Nakatani N. Antioxidant activity of chemical components from sage (Salvia officinalis L.) and thyme (Thymus vulgaris L.) measured by the oil stability index method. J Agric Food Chem 2002;50(7):1845-1851.

Nostro A, Blanco AR, Cannatelli MA, et al. Susceptibility of methicillin-resistant staphylococci to oregano essential oil, carvacrol and thymol. FEMS Microbiol Lett 2004;230(2):191-195.

Westermeyer RR, Terpolilli RN. Cardiac asystole after mouthwash ingestion: a case report and review of the contents. Mil Med 2001;166(9):833-835.

Youdim KA, Deans SG. Effect of thyme oil and thymol dietary supplementation on the antioxidant status and fatty acid composition of the ageing rat brain. Br J Nutr 2000;83(1):87-93.

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.